SimpleX Chat
Chat & CommunicationPrivate messenger without any user identifiers
Replaces Signal, WhatsApp
Best Cross-Platform Chat & Communication for self-hosting
The 50 best Cross-Platform chat & communication you can self-host, ranked by community traction.
Screego
Chat & CommunicationScreen sharing for developers
Berty
Chat & CommunicationPeer-to-peer messaging app that works offline
Replaces WhatsApp, Signal
Mumble
Chat & CommunicationLow-latency, high-quality voice chat application
Replaces Discord, TeamSpeak
The Lounge
Chat & CommunicationModern, self-hosted web IRC client
Replaces IRCCloud, Slack
Ferdium
Chat & CommunicationAll-in-one messenger that combines chat services
Replaces Rambox, Station
WeeChat
Chat & CommunicationExtensible terminal-based chat client
Replaces Slack
irssi
Chat & CommunicationModular terminal IRC client with scripting
Replaces Slack
Tox
Chat & CommunicationPeer-to-peer encrypted messaging protocol and core
Replaces Skype, Discord
Stoat
Chat & CommunicationStoat is a user-first chat platform built with modern web technologies
Chitchatter
Chat & CommunicationPeer-to-peer chat app that is serverless, decentralized, and ephemeral
Live Helper Chat
Chat & CommunicationLive Support chat for your website
Indico
Chat & CommunicationFeature-rich event management system
Replaces Zoho Backstage
RetroShare
Chat & CommunicationSecured and decentralized communication system
Peer-calls
Chat & CommunicationGroup peer to peer video calls for everyone
Replaces BigBlueButton, Skype
openSIPS
Chat & CommunicationSIP proxy/server for voice, video, IM, presence and any other SIP
mautrix
Chat & CommunicationCollection of Matrix bridges for popular chat networks
Replaces Beeper
Hyphanet
Chat & CommunicationAnonymously share files, browse and publish _freesites_ (web sites
KiwiIRC
Chat & CommunicationHosted-anywhere modern web IRC client
Replaces Slack, Discord
Pretalx
Chat & CommunicationConference management software
Replaces Zoho Backstage
Delta Chat
Chat & CommunicationDecentralized messenger built on top of email
Replaces WhatsApp, Signal
Notifo
Chat & CommunicationMultichannel notification server with support for Email, Mobile Push,
OTS
Chat & CommunicationOne-Time-Secret sharing platform with a symmetric 256bit AES
Quassel IRC
Chat & CommunicationDistributed IRC client with an always-on core
Replaces Slack
matrix-commander
Chat & CommunicationCommand-line tool for sending and receiving Matrix messages
Replaces Slack CLI
Mumble Web
Chat & CommunicationBrowser-based client for Mumble voice servers
Replaces Discord, TeamSpeak
Session
Chat & CommunicationOnion-routed private messenger with no phone number
Replaces Signal, WhatsApp
Linphone
Chat & CommunicationOpen-source SIP voice, video, and messaging client
Replaces Skype, Zoom
Shhh
Chat & CommunicationKeep secrets out of emails or chat logs, share them using secure links
Gamja
Chat & CommunicationSimple, lightweight web-based IRC client
Replaces IRCCloud
PushBits
Chat & CommunicationNotification server for relaying push notifications via Matrix,
Wesh Network
Chat & CommunicationP2P encrypted messaging protocol toolkit
Replaces Signal, WhatsApp
Zusam
Chat & CommunicationTruly private space for you and your friends
Scuttlebutt Room
Chat & CommunicationSecure Scuttlebutt room server
Robust IRC
Chat & CommunicationIRC without netsplits
Biboumi
Chat & CommunicationXMPP to IRC gateway component
Libervia
Chat & CommunicationMulti-frontend XMPP communication ecosystem
Replaces Slack, Facebook
Jami
Chat & CommunicationFully distributed, peer-to-peer encrypted communication
Replaces Skype, Zoom
MailBag
Chat & CommunicationSimple plaintext email send app
Mailman3
Chat & CommunicationElectronic mailing lists manager
Replaces Google Groups
Mlmmj Web
Chat & CommunicationSimple web frontend for Mlmmj mailing list management
Peachpub
Chat & CommunicationSecure Scuttlebutt pub with a web interface for pub management
Replaces Facebook, Instagram
PrivMX WebMail
Chat & CommunicationAlternative private mail system - web-based, end-to-end encrypted
3CX
Chat & CommunicationFull-featured PABX system, with call queues, built-in web
Groupboard
Chat & CommunicationOnline whiteboard, audio/video conferencing, screen sharing, shared
Wazo
Chat & CommunicationFull-featured IPBX solution built atop Asterisk with integrated Web
Yeti-Switch
Chat & CommunicationTransit class4 softswitch(SBC) with integrated billing and routing
Freepbx
Chat & CommunicationWeb-based open source GUI that controls and manages Asterisk
GNUnet
Chat & CommunicationSoftware framework for decentralized, peer-to-peer networking
SIP3
Chat & CommunicationVoIP troubleshooting and monitoring platform
No apps match these filters.
At a glance
| App | Deploy effort | Difficulty | Min. RAM | License | ★ Stars |
|---|---|---|---|---|---|
| SimpleX Chat | Under-an-hour setup | Medium | 256 MB | AGPL-3.0 | 19,560 |
| Screego | Read-the-docs project | Easy | 50 MB | GPL-3.0 | 10,735 |
| Berty | Read-the-docs project | Hard | 256 MB | Apache-2.0 | 9,325 |
| Mumble | Under-an-hour setup | Easy | 128 MB | BSD-3-Clause | 8,340 |
| The Lounge | Under-an-hour setup | Easy | 256 MB | MIT | 6,355 |
| Ferdium | Under-an-hour setup | Easy | 512 MB | Apache-2.0 | 4,691 |
| WeeChat | Read-the-docs project | Medium | 64 MB | GPL-3.0 | 3,405 |
| irssi | Read-the-docs project | Medium | 32 MB | GPL-2.0 | 3,156 |
| Tox | Read-the-docs project | Medium | 64 MB | GPL-3.0 | 2,693 |
| Stoat | Read-the-docs project | Medium | 512 MB | AGPL-3.0 | 2,675 |
Quick picks
- Most adopted: SimpleX Chat (19,560 GitHub stars).
- Lightest footprint: irssi (from 32 MB RAM, against 800 MB for the heaviest here).
- Licensing: 10 of 50 use GPL-3.0; check the rest individually if you plan to modify and redistribute.
Every option here is open-source and self-hostable, tagged Cross-Platform within the chat & communication category. Deploy effort is graded from published container recipes, not vendor claims — see the methodology.