Chat & messaging services

WhatsApp

whatsapp.com

Messaging service for mobile and web with encrypted conversations, group chat and calls, owned by Meta.

Matrix

matrix.org

Open standard and network for decentralised messaging that several chat clients build on.

Rocket.Chat

rocket.chat

Open source chat platform for organisations with self-hosting and built-in customer service chat.

Zulip

zulip.com

Open source group chat where conversations are organised into topic threads rather than running channels.

Session

getsession.org

Encrypted messaging service without phone number or email, sending via a decentralised network.

SimpleX Chat

simplex.chat

Encrypted messaging app without user accounts or user IDs, built with a focus on anonymity.

Briar

briarproject.org

Encrypted messaging app for Android that can also send directly between phones without internet.

Delta Chat

delta.chat

Chat app that sends messages as ordinary email and so requires no new account.

Free messaging and calling service without central servers, developed under the GNU Project.

Wire

wire.com

Encrypted messaging and meeting platform aimed at businesses and public authorities.

Viber

viber.com

Messaging app with free calls, chat and groups between users.

Threema

threema.com

Swiss messaging app with encryption and use without a phone number.