View source for Software:Comparison of VoIP software

{{short description|Software comparison}}
This is a '''comparison of voice over IP''' ('''VoIP''') '''software''' used to conduct [[Engineering:Telephone|telephone]]-like voice conversations across [[Internet Protocol]] (IP) based networks. For residential markets, [[Engineering:Voice over IP|voice over IP]] phone service is often cheaper than traditional public switched telephone network (PSTN) service and can remove geographic restrictions to telephone numbers, e.g., have a PSTN phone number in a New York area code ring in Tokyo.

For businesses, VoIP obviates separate voice and data pipelines, channelling both types of traffic through the IP network while giving the telephony user a range of advanced abilities.

[[Software:Softphone|Softphone]]s are client devices for making and receiving voice and video calls over the IP network with the standard functions of most ''original'' telephones and usually allow integration with VoIP phones and [[Engineering:USB phone|USB phone]]s instead of using a computer's microphone and speakers (or headset). Most softphone clients run on the open [[Session Initiation Protocol]] (SIP) supporting various codecs. [[Software:Skype|Skype]] runs on a closed proprietary networking protocol but additional [[Engineering:Business telephone system|business telephone system]] (PBX) software can allow a SIP based telephone system to connect to the Skype network.<ref name="skypesip">{{cite web|title=Skype Connect...|url=http://www.skype.com/en/features/skype-connect/|website=skype.com|publisher=Microsoft Corporation Inc.|access-date=15 November 2014|archive-url=https://web.archive.org/web/20141111022420/http://www.skype.com/en/features/skype-connect/|archive-date=2014-11-11}}</ref> ''[[Social:Online chat|Online chat]]'' programs now also incorporate voice and video communications.

Other VoIP software applications include conferencing servers, intercom systems, virtual [[Engineering:Foreign exchange service (telecommunications)|foreign exchange service]]s (FXOs) and adapted telephony software which concurrently support VoIP and public switched telephone network (PSTN) like Interactive Voice Response (IVR) systems, dial in dictation, on hold and call recording servers.

Some entries below are Web-based VoIP; most are standalone Desktop applications.

== Desktop applications ==
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In the "License" column, please restrict entries to:
* {{open source|abbreviation}}
* {{proprietary}}
* {{some|Mixed: abbreviation, [[Proprietary software|proprietary]]}} or {{some|Mixed: [[Proprietary software|proprietary]], abbreviation}} depending on which form dominates

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{| class="wikitable sortable"
|-
! Program
! [[Operating system]]s
! [[Software license|License]]
! Costs
! Protocols
! [[Codec]]s
! [[Encryption]]
! Max conference peers
! Other abilities
! Latest release
|-
!{{rh}}| [[Company:AudioCodes|AudioCodes]] MobilityPLUS
| [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]]
| {{proprietary}}
| {{dunno}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]], XMPP, [[STUN]], [[Interactive Connectivity Establishment|ICE]]
| [[G.722]] wideband, [[G.711]]a, [[G.711]]u, iLBC, G.729a, [[Software:SILK|SILK]], GSM, VP8, H.264, Opus
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| {{Unk}}
| Voice, video, IM, Group chat, content sharing, SMS and MMS over IP services, native and social network contacts integration, incoming call/IM push notifications.
| {{Start date and age|2014}}
|-
!{{rh}}| Avaya Application Server 5300 Soft Client
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{dunno}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]]
| {{Unk}}
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| {{Unk}}
| <!-- features -->
| 2.0; {{Start date and age|2010}}
|-
!{{rh}}| [[Software:Blink (SIP client)|Blink]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]]
| {{some|Mixed: free software versions under GNU GPLv3 + shareware versions under gplv3 with exception of including proprietary code}}
| macOS version proprietary on App Store, free version limited to sponsored SIP provider; Windows version proprietary; Linux version open source
| [[Interactive Connectivity Establishment|ICE]], [[Session Initiation Protocol|SIP]], [[Message Session Relay Protocol|MSRP]], [[RFB protocol|RFB (VNC)]], XCAP
| Opus, [[Software:Speex|speex]], [[G.722]], GSM, iLBC, PCMU, [[A-law algorithm|PCMA]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]] and [[ZRTP]] on all versions, [[Software:Off-the-Record Messaging|OTR/SMP]] on Linux and macOS only<ref>{{cite web|title=Download Blink|url=http://icanblink.com/download/|website=Blink Project's Website|date=14 January 2016|access-date=22 June 2016}}</ref>}}
| No limit
| IM, file transfer, desktop sharing, multi-party conference, wideband
| Blink Qt <!--{{Start date and age|201y|mm|dd}}-->
|-
!{{rh}}| [[Software:Battle.net|Battle.net]]
| [[Software:MacOS|macOS]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]], [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| {{Unk}}
| {{Unk}}
| {{Unk}}
| {{Unk}}
| IM, multi-party conference
| {{Unk}}
|-
!{{rh}}| Cisco IP Communicator<ref>{{Cite web|url=https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cipc/8_6_6/Release_Notes.html|title=Release Notes for Cisco IP Communicator 8.6.6|website=Cisco|language=en-US|access-date=2018-04-03}}</ref>
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}} (for Cisco SMB Partners only)
| [[Skinny Client Control Protocol|SCCP]] ([[Skinny Client Control Protocol|Skinny]]), [[Session Initiation Protocol|SIP]], [[Trivial File Transfer Protocol|TFTP]], [[Hypertext Transfer Protocol|HTTP]] (for XML Services)
| [[G.722]] wideband, [[G.711]]a, [[G.711]]u, iLBC, [[Software:Internet Speech Audio Codec|iSAC]], G.729a, [[G.729]]ab
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]]}}
| No limit (with bridge), 2 otherwise<ref>{{Cite web|url=https://www.cisco.com/c/en/us/products/collateral/collaboration-endpoints/ip-communicator/data_sheet_c78-669663.html|title=Cisco IP Communicator 8.6|website=Cisco|language=en|access-date=2018-04-03}}</ref>
| Call Recording, Silent Monitoring, Multiple lines and directory numbers, Configurable speed dial, Calling name and number display, Call Waiting, Call Forward, Call Transfer, Three-Way Calling (conference), Call Park, Call Pickup, Redial, Hold, Barge, Callback, Extension Mobility, Message waiting indicator, iDivert, Meet Me conferencing, Group Pickup, Do Not Disturb, XML Services
| 8.6.6; {{Start date and age|2016|04|27}}
|-
!{{rh}}|  [[Software:Discord|Discord]]
| [[Software:MacOS|macOS]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]], [[Software:Windows|Windows]], [[Software:Linux|Linux]]
| {{proprietary}}
| {{free}}, Premium "Nitro" Subscription for Additional Features.
| [[Real-time Transport Protocol|RTP]], [[User Datagram Protocol|UDP]], [[WebSocket|WS]], [[HTTPS]]
| Opus
|{{Yes|[[Transport Layer Security|TLS]]}}
|5000 soft limit for voice calls,<ref>{{Cite news|url=https://twitter.com/discordapp/status/814546030612148224|title=Discord on Twitter|newspaper=Twitter|access-date=2016-12-29}}</ref> 25 hard limit for video<ref>{{cite web|url=https://blog.discord.com/wave-hello-to-server-video-85dcef1128f0|title=Wave Hello to Server Video|access-date=2020-06-21}}</ref>
|IM, file sharing, in-game overlay
|59746; {{Start date and age|2020|04|24}}
|-
!{{rh}}| [[Software:Ekiga|Ekiga]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], OpenSolaris
| {{open source|[[Software:GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[H.323]], [[STUN]], Zeroconf, XMPP, RTP
| [[H.263]], H.264/MPEG-4 AVC, [[Software:Theora|Theora]], iLBC, Speex, SILK, GSM, ...
| {{No}}
| {{Unk}}
| Video, IM, LDAP, Call Forwarding, Call Transfer, Auto-answering, PC to phone, phone to PC, Multiple accounts, USP support, Message waiting indicator, SIMPLE-based presence etc.
| {{Latest stable software release/Ekiga}}
|-
!{{rh}}| [[Software:Empathy|Empathy]]
| [[Software:Linux|Linux]]
| {{open source|[[Software:GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], XMPP ([[Jingle (protocol)|Jingle]]), [[Interactive Connectivity Establishment|ICE]] ([[STUN]]-[[Traversal Using Relays around NAT|TURN]]), Zeroconf
| {{Unk}}
| {{No}}
| {{Unk}}
| IM, multi-user A/V,<ref>{{cite web|title=Telepathy Q&A from the Boston GNOME Summit|url=http://robot101.net/2009/10/14/telepathy-qa/|access-date=4 February 2014}}</ref>  collaborative applications
| {{Latest stable software release/Empathy (software)}}
|-
!{{rh}}| [[Software:Eyeball Chat|Eyeball Chat]]
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[STUN]], [[Interactive Connectivity Establishment|ICE]], XMPP
| {{Unk}}
| {{Yes}}
| 5<ref>[http://www.eyeballchat.com/index.php?option=com_content&view=article&id=46 Eyeball Chat 3.2 Features] {{Webarchive|url=https://web.archive.org/web/20090321090148/http://www.eyeballchat.com/index.php?option=com_content&view=article&id=46 |date=2009-03-21 }}. EyeballlChat.com.</ref>
| IM, Conferencing, Voice, Video and [[SIMPLE (instant messaging protocol)|SIMPLE]] based presence
| [[Software:Microsoft Windows|Windows]] 3.2; {{Start date and age|2009}}
|-
!{{rh}}| [[Software:FaceTime|FaceTime]]
| [[Software:IOS|iOS]], [[Software:MacOS|macOS]]
| {{proprietary}}
| {{Free}}
| [[Session Initiation Protocol|SIP]], [[IETF]], Signaling protocol for VoIP, [[STUN]], TURN and [[Interactive Connectivity Establishment|ICE]]| [[IETF]], technologies for traversing firewalls and NAT
| H.264 Video, [[AAC-LD|AAC-ELD]] Audio, [[H.263]] and [[Software:VP8|VP8]]
| [[Real-time Transport Protocol|RTP]], [[Secure Real-time Transport Protocol|SRTP]] [[IETF]]|standards for delivering real-time and encrypted media streams for VoIP.
| 20
| Video, voice, conferencing, with additional tools available as "Services".
|
|-
!{{rh}}| [[Software:Google Hangouts|Google Hangouts]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], [[Software:MacOS|macOS]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]]
| {{proprietary}} (using [[Jingle (protocol)|libjingle]])
| {{free}}
| XMPP
| H.264/SVC, H.264/AVC, [[H.263]] and [[Software:VP8|VP8]]
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]]}}
| 10
| Video, chat, screen sharing, with additional tools available as "Hangout Apps".
| {{Latest stable software release/Google+ Hangouts}}
|-
!{{rh}}| IBM Sametime
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]], mobile
| {{proprietary}}
| {{dunno}}
| [[Session Initiation Protocol|SIP]]-[[SIMPLE (instant messaging protocol)|SIMPLE]], T.120
| [[H.323]]
| {{Yes|[[Transport Layer Security|TLS]]}}
| {{Unk}}
| IM, File transfer, Voice, Presence, Server stored contact list, HTTP tunneling, plugins, embedable in Lotus Notes<ref>[http://www-01.ibm.com/software/lotus/products/sametime/telephony.html "Telephony with Lotus Sametime software"]. IBM.com. Retrieved 2010-02-16</ref>
| 8.5.2; {{Start date and age|2011|05|08}}
|-
!{{rh}}| [[Software:Jami|Jami]] by Savoir-faire Linux
| [[Software:Android (operating system)|Android]], [[Software:FreeBSD|FreeBSD]], [[Software:IOS|iOS]], [[Engineering:IPhone|iPhone]], [[Software:Linux|Linux]], [[Software:Microsoft Windows|Microsoft Windows]], [[Software:OS X|OS X]]<ref>{{Cite web|url=https://ring.cx/en/news|title=News|date=2018-07-25|website=Ring|language=en|access-date=2018-12-01|archive-url=https://web.archive.org/web/20181226012459/https://ring.cx/en/news|archive-date=2018-12-26|url-status=dead}}</ref>
| {{open source|[[Software:GNU General Public License|GPL-3.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]], [[STUN]] per account, [[SRV record|SRV]], [[Distributed hash table|DHT]], [[Peer-to-peer|P2P]]
| Audio: Opus, [[Software:Speex|Speex]], [[G.722]], [[G.711]], GSM, [[Software:VP8|VP8]], [[G.729]], iLBC. Video: H.264, [[H.263]], [[Software:VP8|VP8]], [[MPEG-4]]
| {{Yes|Voice encryption ([[Secure Real-time Transport Protocol|SRTP]] with [[SDES]] or [[ZRTP]]) and signaling encryption ([[Transport Layer Security|TLS]]), multiple realms authentication mechanism }}
| No limit
| [[Finance:Blockchain|Blockchain]] ID-management, Gnome-KDE client, address book, multiple accounts, unlimited call number, call transfer, call hold-unhold, call recording, multi-way conferencing
| {{Latest_stable_software_release/Ring_(software)}}
|-
!{{rh}}| [[Software:Jitsi|Jitsi]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]] (all java supported). ''Experimental'' [[Software:Android (operating system)|Android]] builds are also available.<ref>{{cite web|url=https://download.jitsi.org/jitsi/nightly/android/|title=Jitsi (SIP Communicator) Android&nbsp;— Nightly Builds Index|publisher=Jitsi.org|access-date=2014-11-15|archive-url=https://web.archive.org/web/20141129035757/https://download.jitsi.org/jitsi/nightly/android/|archive-date=2014-11-29|url-status=dead}}</ref>
| {{open source|[[Software:Apache License|Apache-2.0]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]-[[SIMPLE (instant messaging protocol)|SIMPLE]], XMPP-[[Jingle (protocol)|Jingle]] [[STUN]] [[Interactive Connectivity Establishment|ICE]], [[Traversal Using Relays around NAT|TURN]]
| [[Software:SILK|SILK]], [[G.722]], [[Software:Speex|Speex]], Opus, [[G.711]] (PCMU/PCMA), iLBC, GSM, [[G.729]], H.264, [[H.263]], [[Software:VP8|VP8]]
| {{Yes|[[ZRTP]], [[Secure Real-time Transport Protocol|SRTP]], [[Software:Off-the-Record Messaging|OTR]], [[Transport Layer Security|TLS]]}}
| {{Unk}}
| Text messaging, audio-video telephony, IPv6 (often broken,<ref>[http://www.internetsociety.org/deploy360/blog/2013/03/video-emil-ivov-about-jitsi-a-voip-softphone-supporting-ipv6-and-dnssec/ Interview with Emil Ivov], Deploy360 blog</ref> P2P not supported<ref>{{cite web |url=https://java.net/jira/browse/JITSI-1166 |title=[#JITSI-1166&#93; P2P IPv6 calls still do not work with explicit IPv6 addresses, no matter if brackets are used&nbsp;— Java.net JIRA |publisher=Java.net |access-date=2014-02-13 |archive-url=https://web.archive.org/web/20140221210327/https://java.net/jira/browse/JITSI-1166 |archive-date=2014-02-21 |url-status=dead }}</ref>), call recording, 64-bit
| {{Latest stable software release/Jitsi}}
|-
!{{rh}}| [[Social:Librestream|Librestream]] Onsight Connect
| [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]]
| {{proprietary}}
| {{dunno}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]], [[STUN]]
| [[G.711]], H.264, MPEG, and others
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| {{Unk}}
| Voice, video, conferencing, image sharing, incoming call/IM push notifications.
| {{Start date and age|2018|02|27}}
|-
!{{rh}}| [[Software:Linphone|Linphone]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], [[Software:MacOS|macOS]], [[Software:Android (operating system)|Android]], [[Engineering:IPhone|iPhone]], [[Engineering:BlackBerry|BlackBerry]]
| {{open source|[[Software:GNU General Public License|GPL-3.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[Software:Speex|Speex]], [[Software:Opus (audio format)|Opus]], G711, GSM, [[G.722]], [[Software:VP8|VP8]] (WebM), H263, MPEG4, [[Software:Theora|Theora]] and H264 (plugin)
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| {{Unk}}
| Video, IM, STUN, IPv6 (disables IPv4 support when enabled), P2P, Secure Encryption, User own Encryption via Provided API https://gitlab.linphone.org/BC/public/linphone-desktop
| 4.2.5; {{Start date and age|2020|06|25}}, provides daily snapshots via http://www.linphone.org/snapshots
|-
!{{rh}}| [[Software:Messages (Apple)|Messages]]
| [[Software:MacOS|macOS]]
| {{proprietary}}
| {{free}}, only [[Software:MacOS|macOS]] and [[Software:IOS|iOS]]
| [[Session Initiation Protocol|SIP]] AIM [[Software:ICQ|ICQ]] XMPP
| H263, H264
| {{Unk}}
| {{Unk}}
| Integrated, PBX independent
| 7.0; {{Start date and age|2012|07|25}}
|-
!{{rh}}| [[Software:MicroSIP|MicroSIP]]
| [[Software:Microsoft Windows|Windows]]
| {{open source|[[Software:GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[STUN]], [[Interactive Connectivity Establishment|ICE]], [[SIMPLE (instant messaging protocol)|SIMPLE]]
| [[Software:Speex|Speex]], iLBC, GSM, [[G.711]], [[G.722]], [[G.729]], [[Software:SILK|SILK]], Linear PCM
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| {{Unk}}
| Video, voice, IM and Presence
| {{Latest stable software release/MicroSIP}}
|-
!{{rh}}| [[Software:Movim|Movim]]
| Any, [[Software:Progressive web application|Progressive web application]]
| {{open source|[[Software:GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[XMPP]], [[STUN]], TURN
| Depending the web-browser
| {{Yes|[[Transport Layer Security|TLS]]}}
| 2
| IM, microblogging, social-network, OMEMO encryption, screen-sharing, file transfer
| {{wikidata|qualifier|raw|preferred|single|Q3326936|P348|P548=Q2804309|P577}}
|-
!{{rh}}| [[Software:Mumble|Mumble]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:IOS|iOS]], [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]]
| {{open source|New BSD license}}
| {{free}}
| [[Interactive Connectivity Establishment|ICE]]
| [[Software:CELT|CELT]], [[Software:Speex|Speex]], Opus
| {{Yes|[[Transport Layer Security|TLS]] and [[OCB mode|OCB-AES128]]}}
| No limit (limited only by server bandwidth and memory)
|Chat with (limited) embedded HTML, Automatic Gain Control, very low [[Engineering:Latency (audio)|latency]], Access Control Lists for user management, Customizable In-Game Overlay for OpenGL and DirectX, Directional Audio, Plugin Support, Nested Channels, Echo cancellation for headset free use, Global Public Server List, Logitech G15 support, Push-To-Talk and Voice-Activation
| 1.4.287; {{Start date and age|2022|09|14}}
|-
!{{rh}}| [[Software:Nymgo|Nymgo]]
| [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]] and [[RTP Control Protocol|RTCP]]
| {{Unk}}
| {{Yes}}
| No limit
|Address Book integration, Call recording/export, Mute, On Hold, Caller ID definition
| 4.2.9; {{Start date and age|2013|03}}
|-
!{{rh}}| oovoo
| [[Software:MacOS|macOS]], [[Software:IOS|iOS]], [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]] and [[RTP Control Protocol|RTCP]]
| {{Unk}}
| {{Yes}}
| 12
|Address Book integration, Call recording/export, Mute, On Hold, Caller ID definition
| 4.2.9; {{Start date and age|2013|03}}
|-
!{{rh}}| [[Software:Phoner|Phoner]]
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Software:Telephony Application Programming Interface|TAPI]], CAPI
| [[G.711]]a, [[G.711]]u, [[G.722]], [[G.726]], [[G.729]], GSM, iLBC, [[Software:Speex|speex]], Opus
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| 8
| Conferencing, call redirection, call recording
| {{Latest stable software release/Phoner}}
|-
!{{rh}}| [[PhonerLite]]
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[G.711]]a, [[G.711]]u, [[G.722]], [[G.726]], [[G.729]], GSM, iLBC, [[Software:Speex|speex]], Opus
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| 8
| Conferencing, call redirection, call recording
| {{Latest stable software release/PhonerLite}}
|-
!{{rh}}| [[Software:QuteCom|QuteCom]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]] XP-2000
| {{open source|[[Software:GNU General Public License|GPL]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[G.711]], [[G.729]], iLBC, AMR-NB, [[G.722]], Speex, AMR-WB ([[G.722.2]]),  [[H.263]], H.263+, H.264, [[Software:Dirac (video compression format)|Dirac]]<ref>{{cite web|title=Supported Codecs|url=http://www.qutecom.org/wiki/SupportedCodecs|website=qutecom.org|access-date=19 December 2014}}</ref>
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], but key exchange via Everbee key Exchange which is not a Standard}}
| {{Unk}}
| Video, [[Social:Instant messaging|IM]] (MSN, AIM, ICQ, Yahoo!, XMPP, [[Software:Google Talk|Google Talk]]), voicemail, wengo to phone, conferencing.
| {{Latest stable software release/QuteCom}}
|-
!{{rh}}| Roger Wilco GameSpy
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| {{dunno}}
| Proprietary
| {{dunno}}
| {{dunno}}
| {{Unk}}
| {{dunno}}
| {{Start date and age|2001}}
|-
!{{rh}}| [[Software:Signal|Signal]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]], [[Engineering:IPhone|iPhone]]
| {{open source|GPLv3 clients and AGPLv3 server}}
| {{free}}
|RingRTC ([[Software:WebRTC|WebRTC]] over [[Signal Protocol|Signal protocol]]<ref name=":0">{{Cite web|url=https://signal.org/blog/signal-video-calls-beta/|title=Video calls for Signal now in public beta|date=2017-03-13|website=Signal|access-date=2020-03-02}}</ref>)
|[[Software:Opus (audio format)|Opus]]<ref name=":0" />
| {{dunno}}
| {{Unk}}
| Signal also allows users to send text messages, files, voice notes, pictures, GIFs, and video messages over a Wi-Fi or data connection to other Signal users on iOS, Android and a desktop app. The app also supports group messaging, read receipts and typing indicators, both of which can be disabled.
| {{Multiple releases
  | branch1 = Android
  | version1 = {{wikidata|property|preferred|references|edit|Q19718090|P348|P400=Q94|P548=Q2804309}}
  | date1 = {{wikidata|qualifier|preferred|single|Q19718090|P348|P400=Q94|P548=Q2804309|P577}}
  | branch2 = iOS
  | version2 = {{wikidata|property|preferred|references|edit|Q19718090|P348|P400=Q48493|P548=Q2804309}}
  | date2 = {{wikidata|qualifier|preferred|single|Q19718090|P348|P400=Q48493|P548=Q2804309|P577}}
  | branch3 = Desktop
  | version3 = {{wikidata|property|preferred|references|edit|Q19718090|P348|P400=Q16338|P548=Q2804309}}
  | date3 = {{wikidata|qualifier|preferred|single|Q19718090|P348|P400=Q16338|P548=Q2804309|P577}}
}}
|-
!{{rh}}| [[Software:Skype|Skype]]
| [[Software:Linux|Linux]](with limited functionality),<ref>{{Cite web|url=http://opensourceforu.com/2017/06/microsoft-retire-skype-linux-app-july-1/|title = Microsoft to retire Skype Linux app on July 1|date = 9 June 2017}}</ref> [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]] 2000-XP-Vista-7-[[Software:Windows Mobile|Mobile]] (unsupported<!--https://support.skype.com/faq/fa10411/Why-can-t-I-download-Skype-Lite-or-Skype-for-Windows-phones-->), [[Software:Binary Runtime Environment for Wireless|BREW]], [[Software:Windows Phone|Windows Phone]], [[Software:Android (operating system)|Android]], [[Engineering:IPhone|iPhone]], [[Engineering:PlayStation Portable|PSP]]
| {{proprietary}}
| {{free}}
| Proprietary P2P protocol {{efn|It is possible to connect by SIP to the Skype network via additional "Skype Connect" PBX software and alternative (SIP) client software/hardware. Neither the Skype ''software'' nor the Skype ''network'' supports SIP directly<ref name="skypesip"/>}}
| [[Software:SILK|SILK]]
| {{Yes|[[Transport Layer Security|TLS]]}}
| 25 starting with version 3.6.0.216. 10 with 2.x
| Conferencing, video, file transfer, voicemail, Skype to phone, phone to Skype, additional P2P extensions (games, whiteboard, etc...); depending on platform.<!-- E.g. no video and P2P on Windows Mobile -->
| {{Latest stable software release/Skype}}
|-
!Steam Chat
|Web, Phones, Desktop
| {{proprietary}}
|
|WebRTC
|
|
|
|
|
|-
!{{rh}}| [[Software:TeamSpeak|TeamSpeak]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], [[Software:MacOS|macOS]], [[Software:FreeBSD|FreeBSD]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]]
| {{proprietary}}
| {{free}}
| {{Unk}}
| [[Software:CELT|CELT]], [[Software:Speex|Speex]] (both until server version 3.5.0), [[Software:Opus (audio format)|Opus]]<ref>{{cite web|url=http://www.teamspeak.com/?page=newsarchive&ident=20130304 |title=New TeamSpeak3 Client and Server released today |publisher=TeamSpeak Systems GmbH |access-date=2015-08-04}}</ref>
| {{Yes}}
| 32 unlicensed, 512 with Non-Profit License (available until September 2018), up to 1024 (Gamer License), 2000
| Simultaneous server conferencing with tabs, 3D sound effects, scalable permissions system, firewall friendly file transfers, in-game overlay for DirectX & OpenGL games, global public server list, plugin system
| 3.5.5; {{Start date and age|2020|11|04}}
|-
!{{rh}}| [[Software:TeamTalk|TeamTalk]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], [[Software:MacOS|macOS]], [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]], [[Software:Raspbian|Raspbian]]
| {{proprietary}}
| {{free}}
| {{proprietary}}
| [[Software:Opus (audio format)|Opus]], [[Software:Speex|Speex]], [[Software:VP8|VP8]]
| {{No}}
| 1000
| Video, file sharing, desktop sharing, stream media files ([[MP3]], [[Audio Video Interleave|AVI]])
| 5.3.3; {{Start date and age|2018|11}}
|-
!{{rh}}| [[Software:TeamViewer|TeamViewer]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], [[Software:MacOS|macOS]], iOS, Android<ref>{{cite web|title=TeamViewer overview|url=http://www.getapp.com/teamviewer-application#overview|publisher=GetApp}}</ref>
| {{proprietary}}
| {{free}} (personal use only)
| {{Unk}}
| {{Unk}}
| {{Yes|AES256}}
| {{Unk}}
| {{Unk}}
| {{Latest stable software release/TeamViewer}}
|-
!{{rh}}| [[Software:Telephone (application)|Telephone]]
| [[Software:MacOS|macOS]] 10.10.2
| {{open source|[[Software:BSD licenses|BSD]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[STUN]], [[Interactive Connectivity Establishment|ICE]]
| {{Unk}}
| {{No}}
| {{Unk}}
| Address Book integration
| 1.1.4; {{Start date and age|2012|03|06}}
|-
!{{rh}}| Toktumi Unlimited, Line2 Pro
| [[Software:Microsoft Windows|Windows]] XP-Vista-7, [[Software:MacOS|macOS]], [[Software:IOS|iOS]], [[Software:Android (operating system)|Android]]
| {{proprietary}}
| {{free}}
| Proprietary with [[Session Initiation Protocol|SIP]] core
| {{Unk}}
| {{Unk}}
| 20
| Conferencing, voicemail, caller ID, call-waiting, address book integration; auto-attendant, call-forwarding
| Windows; {{Start date and age|2010|08}}; macOS; {{Start date and age|2010|10}}
|-
!{{rh}}| [[Software:Tox (protocol)|Tox]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]], [[Software:Android (operating system)|Android]], [[Software:FreeBSD|FreeBSD]]
| {{open source|[[Software:GNU General Public License|GPL-3.0-or-later]]}}
| {{free}}
| [[Software:Tox (protocol)|Tox]], [[Software:VP8|VP8]]
| Opus,
| {{Yes|[[Software:NaCl|NaCl]]}}
| {{Unk}}
| Voice, video, instant messaging, file transfers
| {{Unk}}
|-
!{{rh}}| Tru App
| [[Software:Microsoft Windows|Windows]] 2000-XP-Vista-7, [[Software:MacOS|macOS]], [[Software:Linux|Linux]]<br />[[Software:IOS|iOS]], [[Software:Android (operating system)|Android]], [[Software:Symbian|Symbian]], [[Software:BlackBerry OS|BlackBerry OS]],
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], XMPP
| {{Unk}}
| {{Unk}}
| {{Unk}}
| Chat, file transfer, voicemail, inbound numbers, integration with GTalk, Microsoft Live, Skype
|
|-
!{{rh}}| [[Software:Tuenti|Tuenti]]
| [[Software:Android (operating system)|Android]], [[Engineering:IPhone|iPhone]], [[Software:Windows Phone|Windows Phone]]
| {{proprietary}}
| {{free}}
| [[Software:WebRTC|WebRTC]], [[Session Initiation Protocol|SIP]], XMPP
| [[Software:Internet Low Bitrate Codec|iLBC]], Opus
| Yes
| {{Unk}}
| Voice, video, [[Social:Instant messaging|Instant messaging]], group chat, photo and video sharing, SMS and MMS, native and social network contacts integration, incoming call/IM push notifications.
| 
|-
!{{rh}}| [[Software:Twinkle|Twinkle]]
| [[Software:Linux|Linux]]
| {{open source|[[Software:GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[G.711]] A-law μ-law, [[G.726]], GSM, iLBC, [[Software:Speex|Speex]] narrow wide ultrawide
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| 3
| Conferencing, chat, file transfer, Firefox integration, call redirection, voicemail, support of VoIP-to-Phone services
| {{Latest stable software release/Twinkle}}
|-
!{{rh}}| [[Software:Ventrilo|Ventrilo]]
| [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]], [[Software:IOS|iOS]], [[Software:Android (operating system)|Android]]
| {{proprietary}}
| {{free}}
| {{Unk}}
| {{Unk}}
| {{No}}
| 8
| Conferencing, chat, text-to-speech
| 3.0.8
|-
!{{rh}}| [[Software:Viber|Viber]]
| [[Software:Linux|Linux]],{{efn|name=viber-desktop-restriction|Viber must be first installed on a mobile phone to function on a desktop operating system<ref name=viber-desktop-restriction-2>{{cite web|last1=Brad Chacos|first1=Brad|title=Hands on with Viber's new desktop app: It's no Skype|url=http://www.pcworld.com/article/2038073/hands-on-with-vibers-new-desktop-app-its-no-skype.html|website=www.pcworld.com|publisher=IDG Consumer & SMB|access-date=15 November 2014|archive-url=https://web.archive.org/web/20140725080804/http://www.pcworld.com/article/2038073/hands-on-with-vibers-new-desktop-app-its-no-skype.html|archive-date=2014-07-25|quote=If you don’t have Viber on your phone and try to install the service on your PC, the app will redirect you to its website and ask you to install Viber on your phone first.}}</ref><ref>[https://blogs.wsj.com/digits/2013/05/07/viber-unveils-desktop-app/ Viber Unveils Desktop App]</ref>}} [[Software:MacOS|macOS]],{{efn|name=viber-desktop-restriction}} [[Software:Microsoft Windows|Windows]],{{efn|name=viber-desktop-restriction}} [[Software:Android (operating system)|Android]], [[Software:Bada|Bada]], [[Software:BlackBerry OS|BlackBerry OS]], [[Software:IOS|iOS]], [[Software:Series 40|Series 40]], [[Software:Symbian|Symbian]], [[Software:Windows Phone|Windows Phone]]
| {{proprietary}}
| {{dunno}}
| {{Unk}}
| {{Unk}}
| {{Yes}}<ref name="Lunden-19-April-2016"/>
| {{Unk}}
| Varies by platform: Text, picture and video messaging on all, voice calling only on iPhone, Android and Microsoft's Windows Phone
| {{Latest stable software release/Viber}}
|-
!{{rh}}|[[Company:Vonage|Vonage]]
|Linux, macOS, Windows, Android, iOS
| {{proprietary}}
|not free
|SIP, STUN, ICE, TURN
|Audio: Opus, G.711
Video: VP8
|SRTP
|50
|VoIP, video, instant messaging, presence (SIP SIMPLE), PSTN (inbound and outbound), call waiting, call hold, call forwarding, voicemail, message-waiting indication, 3-way conferencing, contacts integration, receptionist console, video, group chat, content sharing, SMS over IP services, native and social network contacts integration, incoming call/IM push notifications, fax, file sharing, screen sharing (desktop only), number programmability.
|-
!{{rh}}| [[Software:Wire|Wire]]
| Linux, Windows, macOS, iOS, Android, Web
| {{open source|GPLv3}}
|not free
| {{dunno}}
| Audio: [[Software:Opus (audio format)|Opus]]
Video: [[Software:VP8|VP8]]
| {{yes|[[Datagram Transport Layer Security|DTLS]], [[Secure Real-time Transport Protocol|SRTP]]<ref name="Wire Security Whitepaper"/>}}
| 10<ref>{{Cite news|url=https://twitter.com/wire/status/808392988665712644|title=Wire on Twitter|work=Twitter|access-date=2017-02-28|language=en}}</ref>
| End-to-end encryption by default for everything, instant messaging, video call, video group call, file sharing, GIF sharing, push to talk, edit message, delete message (on both side), timed messages, doodling, identity verification, screen sharing (desktop only)
| {{dunno}}
|-
!{{rh}}| [[Software:Yahoo! Messenger|Yahoo! Messenger]]
| [[Software:Classic Mac OS|Classic Mac OS]] (8, 9), [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]], ([[Software:Linux|Linux]], [[Software:FreeBSD|FreeBSD]] version VoIP incapable)
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]] (using [[Transport Layer Security|TLS]]) and RTP (media)
| {{Unk}}
| {{Unk}}
| {{Unk}}
| Video, file transfer, PC to phone, phone to PC
| '''Windows''': 11.5.0.228; {{Start date and age|2012|05|31}}<br /><!--
                       --> '''Mac''': 3.0.1; {{Start date and age|2011|07|20}}<br /><!--
                       --> '''Linux''': 1.0.6; {{Start date and age|2003|09}}<br /><!--
                       --> '''SunOS 5.7''': 0.99.17-1; {{Start date and age|2003|09}}<br /><!--
                       --> '''Solaris 8''': 1.0.4; {{Start date and age|2003|09}}<br /><!--
                       --> '''FreeBSD 4-5''': 1.0.4; {{Start date and age|2003|09}}<br /><!--
                       --> '''iOS''': 2.2.6; {{Start date and age|2012|07|12}}<!--
                           When updating this, don't forget to update Latest releases and Feature history-->
|-
!{{rh}}| [[Software:Yate (telephony engine)|Yate Client]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]]
| {{open source|[[Software:GNU General Public License|GPL]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], XMPP, [[H.323]]
| [[G.711]]a, [[G.711]]u, GSM 06.10, iLBC, [[Software:Speex|Speex]], [[G.723]], [[G.726]], [[G.728]], [[G.729]]
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], maybe [[ZRTP]]?}}
| {{Unk}}
| <!-- abilities -->
| 6.0.0; {{Start date and age|2017|09}}
|-
!{{rh}}| [[Software:Zfone|Zfone]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]]
| {{proprietary}} (with viewable source)
| {{free|Includes time bomb provision}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]]
| {{Unk}}
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| {{Unk}}
| <!-- abilities -->
| Beta 2008-09-04 ([[Software:Linux|Linux]] 0.9.224), ([[Software:MacOS|macOS]] 0.9.246), ([[Software:Microsoft Windows|Windows]] 0.9.206)
|-
|}

{{notelist|close}}

=== Discontinued softphone service ===

{{columns-list|colwidth=18em|
* AOL Instant Messenger
* [[Software:Gizmo5|Gizmo5]]
* [[Software:Windows Live Messenger|Windows Live Messenger]]
}}

== Mobile phones ==
For mobile VoIP clients:
{|class="wikitable sortable"
|-
! Program
! [[Operating system]]s
! [[Software license|License]]
! [[Open-source software|Open source]]
! Protocols
! [[Codec]]s
! [[Encryption]]
! Other abilities
! Latest release
|-
| Acrobits Softphone
| [[Software:Android (operating system)|Android]] v2.2+, [[Software:IOS|iOS]] v7.0+
| {{proprietary}}
| {{No}}
| [[Session Initiation Protocol|SIP]]
| [[G.711]], [[G.722]], iLBC, GSM, [[G.729]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| VOIP over Wi-Fi or 3G iOS only: push notifications, video, number rewriting, address book matching, sms for betamax providers and pennytel
| Acrobits Softphone: 3.20 (Android), 5.2 (iOS)
|-
| [[Software:Google Duo|Google Duo]]
| iOS, Android
| {{proprietary}}, [[Freeware|freeware]]
| {{No}}
| [[Software:WebRTC|WebRTC]]
| {{dunno}}
| {{dunno}}
| One-to-one voice and video calling.
| {{Latest stable software release/Google Duo}}
|-
| [[Software:Jami|Jami]] by Savoir-faire Linux
| [[Software:IOS|iOS]], [[Software:Android (operating system)|Android]]<ref>[https://jami.net/download/] Jami downloads</ref>
| {{open source|[[Software:GNU General Public License|GPLv3]]}} 
| {{Yes}}
| [[Session Initiation Protocol|SIP]] 
| Video: H264, VP8, MP4V, H263, Audio: [[Software:Opus (audio format)|Opus]] 48000 hz, G722 PCMA, PCMU 
| {{yes|[[Secure Real-time Transport Protocol|SRTP]], SIP over [[Transport Layer Security|TLS]] }}
| {{dunno}}
| Version 202103261733 {{Start date and age|2021|03}}
|-
| Jajah Mobile Web
| Symbian, Windows Mobile (version unknown)
| {{Proprietary}}
| {{No}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| web based service, Call back, no download<ref>[http://www.jajah.com/products/mobile-web/ "JAJAH.Mobile Web"] {{webarchive|url=https://web.archive.org/web/20090629044409/http://www.jajah.com/products/mobile-web/ |date=2009-06-29 }}. Jajah.com.</ref>
| {{dunno}}
|-
| JusTex by Juphoon
| Android, [[Software:IOS|iOS]] v5.1+
| {{proprietary}}
| {{No}}
| [[Session Initiation Protocol|SIP]]
| [[A-law algorithm|PCMA]], PCMU, [[G.722]], iLBC, [[Software:Internet Speech Audio Codec|iSAC]], [[Software:Opus (audio format)|Opus]], H.264, [[Software:VP8|VP8]], [[H.263]]
| {{Yes|[[Transport Layer Security|TLS]], [[Transmission Control Protocol|TCP]], UDP, [[Secure Real-time Transport Protocol|SRTP]]}}
| JusTex Softphone over Wi-Fi or 3G, HD voice and video call, Multiparty call, conference.
| 3.0.1 (iOS); {{Start date and age|2014|07|13}}; 3.0 (Android); {{Start date and age|2014|07|09}}
|-
| Line
| Android, iOS
| {{proprietary}}
| {{No}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| 
|-
| Line2
| Android, iOS
| {{proprietary}}, [[Freeware|freeware]]
| {{No}}
| Proprietary with [[Session Initiation Protocol|SIP]] core
| {{dunno}}
| {{dunno}}
| Tri-mode calling (cellular, 3G/4G data, Wi-Fi), SMS over IP, visual voicemail, 20-person conference calls, auto-attendant, call-forwarding
| 1.0.4 Android, 3.2.1 iOS
|-
| [[Software:Signal|Signal]] by the [[Organization:Signal Foundation|Signal Foundation]]
| iOS, Android
| {{open source|[[Software:GNU General Public License|GPLv3]]}}
| {{Yes}}
| [[Software:WebRTC|WebRTC]]<ref name="signal-video-calls-beta">{{cite web|last1=Marlinspike|first1=Moxie|title=Video calls for Signal now in public beta|url=https://whispersystems.org/blog/signal-video-calls-beta/|publisher=Open Whisper Systems|access-date=22 March 2017|date=14 February 2017}}</ref>
| [[Software:Opus (audio format)|Opus]]<ref name="signal-video-calls-beta"/>
| {{Yes|[[Transport Layer Security|TLS]], [[Signal Protocol]]<ref name="signal-video-calls-beta"/>}}
| End-to-end encryption by default for everything. CallKit and location privacy,<ref name="signal-video-calls">{{cite web|last1=Marlinspike|first1=Moxie|title=Video calls for Signal out of beta|url=https://whispersystems.org/blog/signal-video-calls/|publisher=Open Whisper Systems|access-date=22 March 2017|date=13 March 2017}}</ref> one-to-one and group messaging, video calling,<ref name="signal-video-calls"/> image/video sharing, timed messages, identity verification, screenshot blocking. Android only: SMS/MMS messaging, doodling,<ref name="doodles-stickers-censorship">{{cite web|last1=Marlinspike|first1=Moxie|title=Doodles, stickers, and censorship circumvention for Signal Android|url=https://whispersystems.org/blog/doodles-stickers-censorship/|publisher=Open Whisper Systems|access-date=22 March 2017|date=21 December 2016}}</ref> GIF sharing.<ref name="giphy-experiment">{{cite web|last1=Marlinspike|first1=Moxie|title=Signal and GIPHY|url=https://whispersystems.org/blog/giphy-experiment/|publisher=Open Whisper Systems|access-date=22 March 2017|date=1 November 2016}}</ref>
| Android	5.2.3 / 15 September 2023
iOS	6.41.1 / 15 September 2023
Desktop	1.33.4 / 13 September 2023
|-
| [[Software:Sipdroid|Sipdroid]]
| [[Software:Android (operating system)|Android]]
| {{open source|[[Software:GNU General Public License|GPL]]}}
| {{Yes}}
| [[Session Initiation Protocol|SIP]]
| {{dunno}}
| {{dunno}}
| Uses [[Wi-Fi]], [[3G|3G]] or EDGE
| 2.7
|-
| Tango by TangoME Inc.
| iOS, Android, Microsoft Windows, macOS, Windows Phone
| {{proprietary}}, [[Freeware|freeware]]
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| VoIP, Wi-Fi out & in, SMS over IP, call-through & call-back, instant messaging, videoconferencing
| {{dunno}}
|-
| [[Company:Truphone|Truphone]]
| Nokia-Symbian, iOS, Android, BlackBerry
| {{proprietary}}, [[Freeware|freeware]]
| {{No}}
| [[Session Initiation Protocol|SIP]]
| {{dunno}}
| {{dunno}}
| VoIP, Wi-Fi out & in, SMS over IP, call-through & call-back, connection management, provisioning
| Symbian 4.0, iOS 1.11.1
|-
| Vopium
| Symbian, Java ME, Android, BlackBerry RIM, iOS, Windows Mobile 2003 SE and higher
| {{proprietary}}, [[Freeware|freeware]]
| {{No}}
| SIP, MSN, Skype, Yahoo, AOL, ICQ, Google Talk, Facebook & Twitter
| GSM
| {{dunno}}
| Wi-Fi VoIP, GSM call-through, SMS over IP, least cost routing, synchronising-backup mobile contacts and calendar
| 2.0
|-
| [[Software:WhatsApp|WhatsApp]]
|
Android, BlackBerry, iOS, Symbian, Windows Phone
| {{proprietary}}, [[Freeware|freeware]]
| {{No}}
| {{dunno}}
| {{dunno}}
| {{yes|ECDH, [[Secure Real-time Transport Protocol|SRTP]]}}<ref>{{cite web|title=WhatsApp Encryption Overview&nbsp;– Technical white paper|url=https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf|publisher=WhatsApp Inc.|access-date=9 April 2016|date=4 April 2016}}</ref>
| VoIP and instant messaging over Wi-Fi or a data connection.
| {{Latest stable software release/WhatsApp}}
|-
| Windows Mobile 6
| Windows Mobile 6 Professional/Standard
| {{proprietary|[[Proprietary software|Proprietary]]}}
| {{No}}
| [[Session Initiation Protocol|SIP]] to publicly and non-publicly routable servers
| {{dunno}}
| {{dunno}}
| [[Wi-Fi]] Mobile VoIP
| 6.1
|-
| Yuilop
| [[Software:Android (operating system)|Android]], [[Software:IOS|iOS]]
, [[Software:Windows Phone|Windows Phone]], [[Software:BlackBerry OS|BlackBerry OS]]
| {{proprietary}}, [[Freeware|freeware]]
| {{No}}
| [[XMPP]], [[Real-time Transport Protocol|RTP]]
| iLBC
| {{Yes|[[Transport Layer Security|TLS]]}}
| VoIP over 3G-4G-LTE and Wi-fi, SMS, group chat, photo sharing, Location sharing, virtual phone numbers
| {{Latest stable software release/Yuilop}}
|}

== Frameworks and libraries ==
{| class="wikitable sortable"
|-
! Program
! [[Operating system]]s
! [[Software license|License]]
! Protocols, based on, compatible with
! [[Encryption]]
! Other abilities
! Key and target markets
! Latest release
|-
| [[Software:Telepathy|Telepathy]], [[Software:Farstream|Farstream]]
| [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]]
| {{open source|[[Software:GNU Lesser General Public License|LGPL]]}}
| SIP, XMPP ([[Jingle (protocol)|Jingle]]), [[Interactive Connectivity Establishment|ICE]] (STUN/TURN), [[Universal Plug and Play|UPnP]]
| {{No}}
| Multi-user A/V conferencing, IM, collaborative applications
| Mobile devices (Maemo, Meego), Linux desktop or embedded
| spec 0.27.2; {{Start date and age|2013|9|24}}
|-
| [[Open Phone Abstraction Library|OPAL]]
| [[Software:Microsoft Windows|Windows]], [[Software:Linux|Linux]] (including embedded variants), [[Software:MacOS|macOS]]
| {{open source|[[Software:Mozilla Public License|MPL]]}}
| SIP, H.323, IAX2, CAPI, VXML
| {{Unk}}
| Multi-user A/V conferencing, IM, IVR
| Softphones, softswitches, telephony application servers
| 3.14.3; {{Start date and age|2014|10|10}}
|-
| [[Software:OSIP|GNU oSIP]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]], [[Software:MacOS|macOS]], [[Software:Android (operating system)|Android]], [[Engineering:IPhone|iPhone]], [[Engineering:BlackBerry|BlackBerry]]
| {{open source|[[Software:GNU Lesser General Public License|LGPL]]}}
| SIP, SDP
| {{Unk}}
| Multi-user A/V conferencing, IM, IVR
| Softphones, embedded and mobile devices, telephony application servers
| 4.1.0; {{Start date and age|2013|12|18}}
|}

== Server software ==
{| class="wikitable sortable"
|-
! Name
! [[Operating system]]s
! [[Software license|License]]
! Protocols
! [[Encryption]]
! Notable features
! Target markets
! [[Software release life cycle|Latest release]]
|-
| [[Software:3CX Phone System|3CX Phone System]]
| [[Software:Microsoft Windows|Windows]], [[Software:Linux|Linux]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Engineering:Voice over IP|VoIP]]/[[Software:VideoOverIP|VideoOverIP]] calls and conferencing, [[Voicemail|voicemail]] and [[Social:Instant messaging|instant messaging]]
| < 50,000 users
| 18.2; {{Start date and age|2021|12|8}}
|-
| [[Software:AskoziaPBX|AskoziaPBX]]
| [[Standalone program]] ([[Software:Linux|Linux]]-based)
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[H.323]], [[Inter-Asterisk eXchange|IAX]], [[Skinny Client Control Protocol|SCCP]]
| {{No}}
| [[Integrated Services Digital Network|ISDN]], [[Voicemail|voicemail]], conferencing, MOH, [[Engineering:Automatic call distributor|ACD]], [[Interactive voice response|IVR]], call forwarding, [[Software:Call-recording software|call recording]]
| SMEs up to 50 users
| 5.4; {{Start date and age|2017|9|2}}
|-
| Asterisk PBX
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:MacOS|macOS]], [[Software:Solaris (operating system)|Solaris]]
| {{Open source|[[Software:GNU General Public License|GPL-2.0+]], optional: [[Proprietary software|Proprietary]]<ref>{{Cite web|title=Licensing|url=https://www.asterisk.org/products/software/licensing/|url-status=live|archive-url=https://web.archive.org/web/20210117002034if_/https://www.asterisk.org/products/software/licensing/|archive-date=2021-01-17|access-date=2022-02-18|website=Asterisk|language=en-US|df=mdy-all}}</ref>}}
| [[Session Initiation Protocol|SIP]], [[H.323]], [[Inter-Asterisk eXchange|IAX]], [[Media Gateway Control Protocol|MGCP]], [[VoFR]], [[XMPP]], [[Software:Google Talk|Google Talk]], [[Time-division multiplexing|TDM]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Engineering:Voice over IP|VoIP]] gateway, [[Voicemail|voicemail]], basic accounting (expandable with [[Open Database Connectivity|ODBC]]-compliant database), billing, conferencing, hot desking, [[Interactive voice response|IVR]] trees with conditional logic, call waiting, [[Engineering:Automatic call distributor|automated call distribution]]
| Enthusiasts, developers, enterprise users (capacity dependent on server design, scalable across multiple servers)
| {{Latest stable software release/Asterisk}}
|-
| Brekeke SIP Server
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]] [[Software:Windows Server 2016|Server 2016]] and [[Software:Windows Server 2019|Server 2019]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Session Initiation Protocol|SIP]] Registrar/Proxy
| SIP Service Providers, VoIP service providers, Healthcare, Security
| 3.12.2.2; {{Start date and age|2022|1|11}}
|-
| [[Software:Brekeke PBX|Brekeke PBX]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]] [[Software:Windows Server 2016|Server 2016]] and [[Software:Windows Server 2019|Server 2019]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Engineering:Voice over IP|VoIP]]/[[Software:VideoOverIP|VideoOverIP]] calls and conferencing, [[Voicemail|voicemail]]
| Hosted service providers, Mid-large enterprise
| 3.12.2.2; {{Start date and age|2022|1|11}}
|-
| [[Company:Speedflow Communications|CallMax Softswitch]]
| [[Software:Linux|Linux]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[H.323]]
| {{Yes|SSL, [[Transport Layer Security|TLS]], HTTPS}}
| Integrated [[Finance:Invoice|billing]], [[Engineering:IP PBX|IP PBX]], [[Finance:Telephone card|calling card]], call shop, web portal, retail [[SMS]]
| SIP Service Providers, Residential & Business VoIP providers, Class 5 [[Engineering:Softswitch|softswitch]] users
| 3.6; {{Start date and age|2015|10|1}}
|-
| [[Software:CommuniGate Pro|CommuniGate Pro]]
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]], [[Software:Solaris (operating system)|Solaris]], [[Software:HP-UX|HP-UX]], [[Software:IBM AIX|AIX]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[XIMSS]], [[XMPP]], [[Software:WebRTC|WebRTC]]
| {{Yes|SSL, [[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Session Initiation Protocol|SIP]] Registrar/Proxy, Authentication, [[Diameter (protocol)|Diameter]], [[RADIUS]], ENUM
| [[Engineering:Mobile network operator|Mobile network operator]]s, ISPs, [[Software as a service|SaaS]] providers
| 6.2.14; {{Start date and age|2019|08|16}}
|-
| [[Software:Dial Gate VoIP Softswitch|Dial Gate VoIP Softswitch]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Billing server, real-time account and line monitoring, web portal
| [[Engineering:Softswitch|Softswitch]] users, service providers
| 4.3; {{Start date and age|2014|06|01}}
|-
| [[Software:Dial-Office IP-PBX|Dial-Office IP-PBX]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Unified communications, conference calls, remote worker support and [[Voicemail|voicemail]]
| Small businesses, Mid-large enterprises
| 4.1; {{Start date and age|2013|12}}
|-
| [[Software:Elastix|Elastix]]
| [[Software:Linux|Linux]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[XMPP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Unified communication server that also supports chat, mail and fax.
| Capacity dependent on server design, scalable across multiple servers
| 5.0.0; {{Start date and age|2016|12|07}}
|-
| [[Software:FreeSWITCH|FreeSWITCH]]
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:MacOS|macOS]], [[Software:Solaris (operating system)|Solaris]], [[Software:Microsoft Windows|Windows]]
| {{open source|[[Software:Mozilla Public License|Mozilla Public License]]}}
| [[Session Initiation Protocol|SIP]], NAT-PMP, [[STUN]], [[SIMPLE (instant messaging protocol)|SIMPLE]], XMPP, [[Software:Google Talk|Google Talk]] ([[Jingle (protocol)|Jingle]]), [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[Media Resource Control Protocol|MRCP]], [[RSS]]<!-- Which one? Does this refer to "Really Simple Syndication", "Rich Site Summary", or any other out of the long list available at http://en.wikipedia.org/wiki/RSS_%28disambiguation%29 ? -->, [[Software:Skype|Skype]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| Recording, Voicemail, Conferencing, [[RADIUS]], ENUM, IM Proxy, Streaming, Media gateway, Soft-PBX, IVR (modular)
| Large soft-switch users, home PBX users, softphone users
| {{Latest stable software release/FreeSWITCH}}
|-
| [[Software:FreePBX|FreePBX]]
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:Solaris (operating system)|Solaris]]
| {{open source|[[Software:GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[XMPP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Complete PABX Service, based on Asterisk and PHP 5.6; provides a full replacement for a legacy non-VoIP phone system; under current and active development
| Scales from Raspberry PI (3 users) to multiple parallel clusters (10K+ simultaneous calls)
| 14.0; {{Start date and age|2017|8|}}
|-
| [[Software:GNU Gatekeeper|GNU Gatekeeper]]
| [[Software:Linux|Linux]], [[Software:FreeBSD|FreeBSD]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]] XP-2000-Vista-7
| {{open source|[[Software:GNU General Public License|GPL]]}}
| [[H.323]]
| {{Yes|[[H.235]]}}
| H.460.18 firewall traversal, routing, accounting
| video conferencing, VoIP carriers large and small
| 3.7; {{Start date and age|2014|08|15}}
|-
| [[Software:HERO Hosted PBX|HERO Hosted PBX]]
| [[Software:Linux|Linux]], [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Unified Communications, billing server, cloud-based management and web interface
| Mid-large enterprises, VoIP carriers and service providers, telecom operators
| 4.3; {{Start date and age|2013|12}}
|-
| Kerio Operator
| [[Software:Linux|Linux]], [[Virtual machine|VM]]
| {{proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|SSL]], [[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| integrated firewall, Auto attendant, Call queues, Conference calling, Call forwarding, pickup, parking, recording, Click to Call, Video calling, Fax support, Paging, [[Company:Salesforce.com|Salesforce]].com and CRM integration, Voicemail to email, complementary desktop Softphone app
| SME
| 2.5.2; {{Start date and age|2016|11|15}}
|-
| [[Company:Speedflow Communications|MediaCore SBC]]
| [[Software:Linux|Linux]]
| {{proprietary}}
| [[H.323]], [[Session Initiation Protocol|SIP]], [[Short Message Peer-to-Peer|SMPP]], [[Hypertext Transfer Protocol|HTTP]]
| {{yes|SSL, [[Transport Layer Security|TLS]], HTTPS}}
| Dynamic routing mechanisms: LCR, jurisdictional and origin-based; integrated [[Finance:Invoice|billing]], SIP-H.323 protocol converter, [[Engineering:Transcoding|transcoding]], [[Finance:Revenue assurance|revenue assurance]], [[Session border controller|SBC]], full and media proxies, wholesale messaging and [[SMS]] hubbing 
| Transit VoIP services providers, VoIP wholesale carriers, VoIP termination providers, Wholesale messaging providers
| 4.8; {{Start date and age|2021|02}}
|-
| [[Software:Mumble|Murmur]]
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]]
| {{open source|[[Software:BSD licenses|BSD]], [[Software:GNU General Public License|GPL]]}}
| [[Software:CELT|CELT]], [[Software:Speex|Speex]], Opus
| {{yes|[[Transport Layer Security|TLS]]}}
|Chat with (limited) embedded HTML, ACLs for user management, Customizable In-Game Overlay, Directional Audio, Plugin Support, Nested Channels
| Individuals to Small and medium enterprise (25-5000 users)
| 1.2.17; {{Start date and age|2016|09|24}}
|-
| Objectworld UC Server
| [[Software:Microsoft Windows|Windows]] XP-2003-2008
| {{proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{no}}
| [[Engineering:IP PBX|IP PBX]], personal assistants, IVR, automated phone provisioning, fax server, unified messaging, Outlook, Exchange and Lotus Domino-Notes integration, conferencing, outbound dialing
| Small and medium enterprise (25-2000 users)
| 4.4.2; {{Start date and age|2009|05}}
|-
| [[Software:Kamailio|Kamailio]], OpenSIPS (formerly named OpenSER)
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:Solaris (operating system)|Solaris]]
| {{open source|[[Software:GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]], XMPP
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Session Initiation Protocol|SIP]] registrar-proxy, authentication, [[Diameter (protocol)|Diameter]], [[RADIUS]], ENUM, least-cost-routing, many others
| SIP Service Providers
| 5.2.8; {{Start date and age|2020|10}}
|-
| SIP Express Router (SER)
| [[Software:Linux|Linux]], [[Software:Berkeley Software Distribution|BSD]], [[Software:Solaris (operating system)|Solaris]]
| {{open source|[[Software:GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]]
| {{no}}
| [[Session Initiation Protocol|SIP]] Registrar/Proxy, Authentication, [[Diameter (protocol)|Diameter]], [[RADIUS]], ENUM, many others
| SIP Service Providers
| 2.0.0 Ottendorf
|-
| sipXecs IP PBX
| [[Software:Linux|Linux]]
| {{open source|[[Affero General Public License|AGPL]]}}
| Native [[Session Initiation Protocol|SIP]] call control, XMPP
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Full redundancy (HA), instant messaging, voicemail, user portal, admin GUI, plug & play management including phones and gateways, fully featured
| Enterprises between 10 and 10,000 users, multi-site
| 14.04.2; {{Start date and age|2014|07}}
|-
| [[Software:VzRoom|vzRoom]]
| [[Software:Microsoft Windows|Windows]]
| {{proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{yes|SSL, [[Transport Layer Security|TLS]], [[Advanced Encryption Standard|AES]]}}
| Instant messaging-chat, VoIP, video, sharing (desktop, video, file), whiteboard, scheduler, recording
| Individual to small and medium enterprise (2-1,000 users)
| 0.8.8.735; {{Start date and age|2010|11}}
|-
| [[Software:Yate (telephony engine)|Yate]]
| [[Software:Berkeley Software Distribution|BSD]], [[Software:Linux|Linux]], [[Software:MacOS|macOS]], [[Software:Microsoft Windows|Windows]]
| {{open source|[[Software:GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[H.323]], ISDN, XMPP (Jabber), [[Jingle (protocol)|Jingle]] ([[Software:Google Talk|Google Talk]]), [[Media Gateway Control Protocol|MGCP]], [[Signalling System No. 7|SS7]] over IP, Cisco SLT (Signalling Link Transport) (SS7 MTP2 backhaul over IP), [[Stream Control Transmission Protocol|SCTP]], [[Skinny Client Control Protocol|SCCP]], TCAP, [[Mobile Application Part|MAP]] CAMEL
| {{yes|SSL, [[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Voice, video, file transfer, data, H323 to SIP signalling proxy, instant messaging, IVR, PC2Phone and Phone2PC gateway, SCCP&nbsp;— GTT routing between networks, Secure Unified Communications, SIP registrar-proxy, SIP SBC (session border controller), USSD, voicemail, VoIP, VoIP to PSTN gateway, conference server (max 200 voice channels per conference), call centre server, prepaid and postpaid cards
| Deployed on home servers and large networks with millions of users
| 6.3; {{Start date and age|2021|02}}
|}

== Secure VoIP software ==

=== VoIP software with client-to-client encryption ===

The following table is an overview of those VoIP clients which (can) provide [[End-to-end encryption|end-to-end encryption]].
{| class="wikitable sortable" style="font-size: smaller; width: 100%; text-align: center;"
|-
! rowspan=2 | Client name
! rowspan=2 | Development status
! rowspan=2 | [[Open-source software|Open source]] client
! rowspan=2 | End-to-end authentication<ref group=lower-alpha name="end-to-end-authentication">End-to-end authentication protects communications from man-in-the-middle attacks by the service provider.</ref>
! colspan=4 | [[Cryptographic protocol|Encryption protocols]]
! rowspan=2 | [[Forward secrecy]]
! rowspan=2 | Multiple encryption
! rowspan=2 | Encrypted group calling
! rowspan=2 | [[Proxy server|Proxy]], [[Software:Tor (anonymity network)|Tor]]
|-
! [[ZRTP]]
! ECDH
! [[Datagram Transport Layer Security|DTLS]]
! [[Secure Real-time Transport Protocol|SRTP]]
|-
! [[Software:FaceTime|FaceTime]]
| {{Active}}
| {{no}}<ref name="EFF"/>
| {{no}}<ref name="EFF"/>
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{yes}}<ref name="EFF"/>
| {{dunno}}
| {{no}}
| {{no}}
|-
! [[Software:Google Duo|Google Duo]]
| {{Active}}
| {{no}}
| {{no}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{no}}
| {{no}}
|-
! [[Software:Jami|Jami]] by Savoir-faire Linux
| {{Active}}
| {{yes}}
| {{yes}}
| {{no}}
| {{dunno}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{dunno}}
| {{yes}}
| {{dunno}}
|-
! [[Software:Jitsi|Jitsi]]<ref group=lower-alpha name="sip-encryption">Only if the user has registered with a compatible SIP provider. Some SIP providers do not support certain encryption protocols.</ref>
| {{Active}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{no}}
| {{yes}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{yes}}
| {{dunno}}
|-
! Line<ref name="Line-2016-08-10">{{cite web|title="Letter Sealing" End-to-End Encryption Indicator Icon Introduced to LINE Messaging App|url=https://linecorp.com/en/pr/news/en/2016/1464|publisher=Line Corporation|access-date=29 September 2016|date=10 August 2016}}</ref><ref name="Shin-2016-08-11">{{cite web|author1=Shin, Ki Bin|title=The next step for even safer messaging: Letter Sealing|url=http://developers.linecorp.com/blog/?p=3938|publisher=Line Corporation|access-date=30 September 2016|date=11 August 2016|archive-url=https://web.archive.org/web/20161002044533/http://developers.linecorp.com/blog/?p=3938|archive-date=2 October 2016|url-status=dead}}</ref>
| {{Active}}
| {{no}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{no}}<ref name="Line-2016-08-10"/>
| {{no}}
|-
! [[Software:Linphone|Linphone]]<ref group=lower-alpha name="sip-encryption"/>
| {{Active}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{dunno}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{dunno}}
| {{no}}
|-
! [[Software:PGPfone|PGPfone]]
| {{no|Abandonware}}
| {{yes|Viewable source}}<ref>{{cite web|title=PGPfone|url=http://www.pgpi.org/products/pgpfone/|website=pgpi.org|access-date=26 August 2016|date=n.d.|archive-url=https://web.archive.org/web/20001109025300/http://www.pgpi.org/products/pgpfone/|archive-date=9 November 2000|url-status=dead}}</ref>
| {{yes}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
|-
! [[Software:Signal|Signal]]
| {{Active}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{no}}
| {{yes}}
| {{no}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{yes}}
| {{depends}}<ref>{{cite web|last1=Marlinspike|first1=Moxie|title=Video calls for Signal out of beta|url=https://whispersystems.org/blog/signal-video-calls/|publisher=Open Whisper Systems|access-date=30 March 2017|date=13 March 2017}}</ref>
|-
! [[Software:Silent Circle|Silent Phone]]
| {{Active}}
| {{yes|Viewable source}}<ref>{{cite web|title=Is Silent Phone open source?|url=https://www.silentcircle.com/products-and-solutions/technology/zrtp/#is-silent-phone-open-source|website=silentcircle.com|publisher=Silent Circle|access-date=26 August 2016|date=n.d.}}</ref>
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{dunno}}
| {{dunno}}
| {{yes}}
| {{yes}}<ref name="EFF">{{cite web | url = https://www.eff.org/node/82654 | publisher = Electronic Frontier Foundation | title = Secure Messaging Scorecard. Which apps and tools actually keep your messages safe? | date = 4 November 2014 |access-date=11 July 2016}}</ref>
| {{yes}}
| {{yes}}
| {{no}}
|-
! [[Software:Skype|Skype]]<br>(opt-in per conversation,<br>one pair of devices per conversation)<ref>{{cite web |title=What are Skype Private Conversations? |url=https://support.skype.com/en/faq/FA34824/what-are-skype-private-conversations |website=Skype |publisher=Microsoft |access-date=24 May 2020 |quote=Note: Private conversations can only be accessed on one device at a time.}}</ref>
| {{Active}}
| {{no}}
| {{yes}}<ref>{{cite web |title=What are Skype Private Conversations? --(private conversations white paper)--> Skype Private Conversation Technical white paper |url=https://support.skype.com/en/faq/FA34824/what-are-skype-private-conversations |publisher=Microsoft |access-date=24 May 2020 |quote=Users can verify the security of their conversations by checking the key setup between two users.}}</ref>
| {{no}}
| {{no}}
| {{no}}
| {{yes}}<ref>{{cite web |title=What are Skype Private Conversations? --(private conversations white paper)--> Skype Private Conversation Technical white paper |url=https://support.skype.com/en/faq/FA34824/what-are-skype-private-conversations |publisher=Microsoft |access-date=24 May 2020 |quote=Caller encrypts the SRTP using the generated encryption key, which can only be decrypted by the callee. After the call is setup, the media packets are encrypted using the SRTP keys.}}</ref>
| {{dunno}}
| {{dunno}}
| {{no}}
| {{no}}
|-
! Telegram
| {{Active}}
| {{yes}}
| {{yes}}<ref>{{cite web|title=Voice Calls: Secure, Crystal-Clear, AI-Powered|url=https://telegram.org/blog/calls|publisher=Telegram|access-date=30 March 2017|date=30 March 2017}}</ref>
| {{no}}
| {{no}}
| {{no}}
| {{no}}
| {{yes}}
| {{dunno}}
| {{no}}
| {{no}}
|-
! [[Software:Threema|Threema]]
| {{Active}}
| {{partial|Partially}}<ref group=lower-alpha name="encryption-open" /><ref>{{cite web|title=Where can I find Threema's source code?|url=https://threema.ch/en/faq/source_code|website=threema.ch|publisher=Threema|access-date=30 October 2017|date=n.d.}}</ref>
| {{yes}}<ref name="threema-whitepaper">{{cite web|title=Threema cryptography whitepaper|url=https://threema.ch/press-files/2_documentation/cryptography_whitepaper.pdf|website=threema.ch|publisher=Threema|access-date=30 October 2017|date=n.d.}}</ref>
| {{no}}
| {{yes}}<ref name="threema-whitepaper" />
| {{yes}}<ref name="threema-whitepaper" />
| {{yes}}<ref name="threema-whitepaper" />
| {{partial|Partially}}<ref group="lower-alpha" name="threema-forward-secrecy">Only on the network connection, not on the end-to-end layer.</ref><ref name="threema-whitepaper" />
| {{yes}}
| {{no}}
| {{no}}
|-
! [[Software:Viber|Viber]]<ref name="Lunden-19-April-2016">{{cite web|last1=Lunden|first1=Ingrid|title=Viber adds end-to-end encryption and hidden chats as the messaging app privacy wave grows|url=https://techcrunch.com/2016/04/19/viber-adds-end-to-end-encryption-hidden-chats-universal-delete-as-messaging-app-privacy-grows/|website=TechCrunch|publisher=AOL Inc.|access-date=12 July 2016|date=19 April 2016}}</ref>
| {{Active}}
| {{no}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{no}}
|-
! [[Software:WhatsApp|WhatsApp]]
| {{Active}}
| {{partial|Partially}}<ref group=lower-alpha name="encryption-open">Only the encryption related source code is open.</ref><ref name="whatsapp-ows" />
| {{yes}}<ref name="whatsapp-ows">{{cite web|title=WhatsApp Encryption Overview&nbsp;– Technical white paper|url=https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf|publisher=WhatsApp Inc.|access-date=5 April 2016|date=4 April 2016}}</ref>
| {{no}}
| {{yes}}<ref name="whatsapp-ows"/>
| {{no}}
| {{yes}}<ref name="whatsapp-ows"/>
| {{yes}}<ref name="whatsapp-ows"/>
| {{yes}}<ref name="whatsapp-ows"/>
| {{yes}}<ref name="whatsapp-ows"/>
| {{no}}
|-
! [[Software:Wire|Wire]]
| {{Active}}
| {{yes}}
| {{yes}}<ref>{{cite web|title=A major upgrade to calling|website=Medium|publisher=Wire Swiss GmbH|url=https://medium.com/wire-news/a-major-upgrade-to-calling-9ac8780741a1#.5jt0cku16|date=14 March 2017|access-date=14 March 2017}}</ref>
| {{no}}
| {{dunno}}
| {{yes}}<ref name="Wire Security Whitepaper">{{Cite web|url=https://wire.com/resource/Wire%20Security%20Whitepaper/download/|title=Wire Security Whitepaper|publisher=Wire Swiss GmbH|access-date=13 April 2016}} </ref>
| {{yes}}<ref name="Wire Security Whitepaper"/>
| {{yes}}<ref>{{cite web |title=Security & Privacy |url=https://wire.com/en/security/ |website=Wire |access-date=19 January 2020 |quote=New encryption keys are used for each message, so a compromised key has minimal impact.}}</ref>
| {{yes}}
| {{yes}}
| {{no}}
|-
! [[Software:Zfone|Zfone]]
| {{no|Abandonware}}
| {{yes|Viewable source}}<ref>{{cite web|url=http://zfoneproject.com/faq.html#opensource|title=Is Zfone open source?|website=zfoneproject.com|publisher=Zfone|access-date=26 August 2016|date=2006}}</ref>
| {{yes}}
| {{yes}}
| {{optional}}<ref>{{cite web|url=http://zfoneproject.com/faq.html#suiteb|title=Do you support Elliptic Curve Diffie-Hellman?|website=zfoneproject.com|publisher=Zfone|access-date=26 August 2016|date=2006}}</ref>
| {{dunno}}
| {{yes}}<ref>{{cite web|url=http://zfoneproject.com/faq.html#srtp|title=Why do we need ZRTP if we already have SRTP? Isn't SRTP good enough?|website=zfoneproject.com|publisher=Zfone|access-date=26 August 2016|date=2006}}</ref>
| {{yes}}
| {{yes}}
| {{dunno}}
| {{dunno}}
|-
|}

=== VoIP software with client-to-server encryption ===
The following table is an overview of those VoIP clients which (normally) provide client-to-server encryption.

{| class="wikitable sortable" style="font-size: smaller; width: 40%; text-align: center; background:none;"
|- class="sortbottom"
|-
! Client name
! [[Cryptographic protocol|Encryption protocols]]
|-
! [[Software:Google Hangouts|Google Hangouts]]<ref name="EFF"/>
| {{yes|[[Secure Real-time Transport Protocol|SRTP]]}}<ref>{{Cite web|url=https://support.google.com/hangouts/answer/6046115|title = Fix problems with Hangouts - Hangouts Help}}</ref>
|-
! [[Software:Skype|Skype]]<ref name="EFF"/>
| {{yes-no|[[Skype protocol|A custom protocol]]}}
|-
|}

;Notes
{{Reflist|group=lower-alpha}}

== See also ==
* [[Comparison of audio coding formats]]
* [[Software:Comparison of cross-platform instant messaging clients|Comparison of cross-platform instant messaging clients]]
* [[Comparison of web conferencing software]]
* [[List of codecs]]
* [[Software:List of SIP software|List of SIP software]]
* List of video telecommunication services and product brands
* [[Matrix (protocol)]]
* [[Secure communication]]
* [[Social:Comparison of user features of messaging platforms|Comparison of user features of messaging platforms]]

== References ==
{{Reflist|30em}}

{{Telecommunications}}

{{DEFAULTSORT:Comparison Of Voip Software}}
[[Category:VoIP software]]
[[Category:Cryptographic software]]

{{Sourceattribution|Comparison of VoIP software}}