The landscape for instant messaging involves cross-platform instant messaging clients that can handle one or multiple protocols. Clients that use the same protocol can typically federate and talk to one another. The following table compares general and technical information for cross-platform instant messaging clients in active development, each of which have their own article that provide further information.
Jitsi is a collection of free and open-source multiplatform voice (VoIP), video conferencing and instant messaging applications for the Web platform, Windows, Linux, macOS, iOS and Android. The Jitsi project began with the Jitsi Desktop. With the growth of WebRTC, the project team focus shifted to the Jitsi Videobridge for allowing web-based multi-party video calling. Later the team added Jitsi Meet, a full video conferencing application that includes web, Android, and iOS clients. Jitsi also operates meet.jit.si, a version of Jitsi Meet hosted by Jitsi for free community use. Other projects include: Jigasi, lib-jitsi-meet, Jidesha, and Jitsi.
Jami is a SIP-compatible distributed peer-to-peer softphone and SIP-based instant messenger for Linux, Microsoft Windows, macOS, iOS, and Android. Jami was developed and maintained by the Canadian company Savoir-faire Linux, and with the help of a global community of users and contributors, Jami positions itself as a potential free Skype replacement.
Cryptocat is a discontinued open-source desktop application intended to allow encrypted online chatting available for Windows, OS X, and Linux. It uses end-to-end encryption to secure all communications to other Cryptocat users. Users are given the option of independently verifying their buddies' device lists and are notified when a buddy's device list is modified and all updates are verified through the built-in update downloader.
Silent Circle is an encrypted communications firm based in Washington DC. Silent Circle provides multi-platform secure communication services for mobile devices and desktops. Launched October 16, 2012, the company operates under a subscription business model. The encryption part of the software used is free software/open source and peer-reviewed. For the remaining parts of Silent Phone and Silent Text, the source code is available on GitHub, but under proprietary software licenses.
The Guardian Project is a global collective of software developers, designers, advocates, activists, and trainers who develop open-source mobile security software and operating system enhancements. They also create customized mobile devices to help individuals communicate more freely and protect themselves from intrusion and monitoring. The effort specifically focuses on users who live or work in high-risk situations and who often face constant surveillance and intrusion attempts into their mobile devices and communication streams.
Wickr is an American software company based in New York City, known for its instant messenger application with the same name. The Wickr instant messaging apps allow users to exchange end-to-end encrypted and content-expiring messages, and are designed for iOS, Android, Mac, Windows, and Linux operating systems. Wickr was acquired by Amazon Web Services (AWS) mid-2021. They discontinued the free version of the app in December 2023.
ChatSecure is a messaging application for iOS which allows OTR and OMEMO encryption for the XMPP protocol. ChatSecure is free and open source software available under the GPL-3.0-or-later license.
TextSecure was an encrypted messaging application for Android that was developed from 2010 to 2015. It was a predecessor to Signal and the first application to use the Signal Protocol, which has since been implemented into WhatsApp and other applications. TextSecure used end-to-end encryption to secure the transmission of text messages, group messages, attachments and media messages to other TextSecure users.
Open Whisper Systems was a software development group that was founded by Moxie Marlinspike in 2013. The group picked up the open source development of TextSecure and RedPhone, and was later responsible for starting the development of the Signal Protocol and the Signal messaging app. In 2018, Signal Messenger was incorporated as an LLC by Moxie Marlinspike and Brian Acton and then rolled under the independent 501c3 non-profit Signal Technology Foundation. Today, the Signal app is developed by Signal Messenger LLC, which is funded by the Signal Technology Foundation.
Threema is a paid cross-platform encrypted instant messaging app developed by Threema GmbH in Switzerland and launched in 2012. The service operates on a decentralized architecture and offers end-to-end encryption. Users can make voice and video calls, send photos, files, and voice notes, share locations, and make groups. Unlike many other popular secure messaging apps, Threema does not require phone numbers or email addresses for registration, only a one-time purchase that can be paid via an app store or anonymously with Bitcoin or cash.
Wire Swiss GmbH is a software company with headquarters in Zug, Switzerland. Its development center is in Berlin, Germany. The company is best known for its messaging application called Wire.
Signal is an encrypted messaging service for instant messaging, voice calls, and video calls. The instant messaging function includes sending text, voice notes, images, videos, and other files. Communication may be one-to-one between users or may involve group messaging.
Peerio was a cross-platform end-to-end encrypted application that provided secure messaging, file sharing, and cloud file storage. Peerio was available as an application for iOS, Android, macOS, Windows, and Linux. Peerio (Legacy) was originally released on 14 January 2015, and was replaced by Peerio 2 on 15 June 2017. The app is discontinued.
FBReader is an e-book reader for Linux, Microsoft Windows, Android, and other platforms.
Wire is an encrypted communication and collaboration app created by Wire Swiss. It is available for iOS, Android, Windows, macOS, Linux, and web browsers such as Firefox. Wire offers a collaboration suite featuring messenger, voice calls, video calls, conference calls, file-sharing, and external collaboration – all protected by a secure end-to-end-encryption. Wire offers three solutions built on its security technology: Wire Pro – which offers Wire's collaboration feature for businesses, Wire Enterprise – includes Wire Pro capabilities with added features for large-scale or regulated organizations, and Wire Red – the on-demand crisis collaboration suite. They also offer Wire Personal, which is a secure messaging app for personal use.
Bitwarden is a freemium open-source password management service that stores sensitive information, such as website credentials, in an encrypted vault. The platform offers a variety of client applications, including a web interface, desktop applications, browser extensions, mobile apps, and a command-line interface. Bitwarden offers a free US or European cloud-hosted service as well as the ability to self-host.
UserLAnd Technologies is a free and open-source compatibility layer mobile app that allows Linux distributions, computer programs, computer games and numerical computing programs to run on mobile devices without requiring a root account. UserLAnd also provides a program library of popular free and open-source Linux-based programs to which additional programs and different versions of programs can be added.
xx messenger is a cross-platform decentralized encrypted instant messaging service developed by PrivaTegrity Corporation. Messages are delivered over a variety of mix network first described in 2016. Users can send one-to-one and group messages, which can include voice notes and images.
