The most popular alternative is Telegram, which is free. If that doesn't suit you, our users have ranked more than 100 alternatives to Signal so hopefully you can find a suitable replacement. Other interesting Signal alternatives are Element (Freemium, Open Source), Tox (Free, Open Source), Jitsi (Free, Open Source) and Wire (Free Personal, Open Source).
- 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].[Note]
- RetroShare is a open source cross-platform, private and secure decentralized communication system.
- Protect your communication in transit and on your phone. Silence (formerly SMSSecure) is a full replacement for the default text messaging application: all messages are encrypted locally and messages to other Silence users are encrypted over the air.
- A secure, end-to-end encrypted Swiss instant messenger with a focus on privacy.
- Linphone is one of the most famous open source softphones in the world. It is fully SIP-based, for all calling, presence and IM features.
- An open-source decentralized and encrypted messaging app even without internet connection via Wi-Fi and Bluetooth. Messages are stored securely on your device, not in the cloud. Connect directly with nearby contacts - no Internet access is required.
- Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them!
- ChatSecure is a free and open source messaging app that features OTR encryption over XMPP.
- LINE is a Japanese proprietary application for instant messaging on smartphones and PCs.
- VOIP service by Tencent that can make free video and voice calls no matter where you are.