The best open source alternative to Rakuten Viber is Signal. If that doesn't suit you, our users have ranked more than 100 alternatives to Rakuten Viber and many of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Rakuten Viber are Element, Tox, Wire and Zulip.
An open-source messaging app emphasizing privacy with encrypted communication. Share texts, calls, photos, and videos without ads or trackers, available across major platforms. Developed by Signal Technology Foundation and praised globally for security measures.
United States
Provides secure collaboration with end-to-end encryption, supporting chat, voice, and video calls. Available on all major platforms, it enables digital sovereignty with a decentralized design and interoperability through bridges to systems like Slack and Teams. Includes enterprise-grade SaaS.
United Kingdom
With the rise of widespread government monitoring programs, Tox is an easy to use application that allows you to connect with friends and loved ones without anyone else listening in.
United States
Secure communication platform featuring encrypted chats and calls, file and media sharing, self-deleting messages, device verification, group collaboration, and customizable settings. Supports use across multiple devices with no phone number required for access.
Switzerland
Threaded group conversations combine live and asynchronous messaging, separating topics for organized collaboration, supporting open-source, cloud, and self-hosted deployments, secure communication with encryption, and multi-platform access for diverse teams.
United States
It is the brand new, and fastest ever, Matrix client. It is for personal and community use, and will support enterprise functionality later this year.
United Kingdom
Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].
Germany
EU
An alternative Telegram client based on TDLib, with higher speed, slicker animations and experimental features.
United Arab Emirates
Self-hosted communication platform with secure audio, video, chat, web conferencing, screensharing, advanced encryption, and metadata privacy, running on user-controlled servers, supporting web and mobile apps, and eliminating third-party data exposure.
GermanyEU
The preservation of privacy is the main driver for this project. Secure technologies, such as WebRTC, are used to establish a direct connection between the participants. The website that provides the web application and mediates the communication stores as little data as...
GermanyEU
Snikket is an ambitious project to build a new kind of XMPP-based messaging platform.
United Kingdom
