The best open source alternative to WhatsApp is Signal. If that doesn't suit you, our users have ranked more than 100 alternatives to WhatsApp and loads of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to WhatsApp are Element, Wire, Tox and Matrix.
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.
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.
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.
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.
Open standard protocol enabling decentralized, encrypted instant messaging, VoIP signaling, IoT device connectivity, and persistent data management across federated servers without central control or single points of failure, bridging communication platforms.
Threema is a new mobile messaging app that puts security first. With true end-to-end encryption, you can rest assured that only you and the intended recipient can read your messages.
Open source decentralized communication platform supporting secure end-to-end encrypted calls, messaging, group conferencing, file and media sharing, SIP compatibility, multi-device sync, and strong privacy, available across desktop and mobile systems.
Open-source video conferencing platform with encryption by default, up to 75 participants, live group chat, HD audio, screen and document sharing, Etherpad editing, mobile and browser support, custom deployment options, privacy-first features, and community-driven development.
Open-source messaging platform enabling private, identifier-free chats, encrypted group discussions, file and media sharing, plus audio and video calls. Employs double-ratchet protocol, stores user data on-device, protects metadata, and lets users self-host relay servers.
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].
Censorship-resistant peer-to-peer messaging that bypasses centralized servers. Connect via Bluetooth, Wi-Fi or Tor, with privacy built-in.
Free and open-source instant messaging and VoIP platform with private DMs, group chats, markdown, file sharing, video calls, screen sharing, moderation tools, quick search, custom emojis, CSS themes, AGPLv3 self-hosting, and multi-device access.
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Signal is an excellent open source WhatsApp alternative, offering simplicity, competitive features, simplicity, and privacy-focused design.