Open-source alternatives guide · Updated 2026
Compare the best free and open-source alternatives to Microsoft Teams — 15 verified projects with explicit catalog relationships. Inspect licenses, GitHub activity, self-hosting signals, and migration fit before you switch.
Official product reference Microsoft Teams↗Only explicit alternative relationships are shown—never inferred competitor claims.
This guide compares 15 verified open-source alternatives to Microsoft Teams, including Rocket.Chat, Mattermost, NextCloud Server, and Jitsi.
Projects appear across Infrastructure, Content & Collaboration, and Productivity. 5 options include a self-hosting signal — see the self-hosted catalog. Ranking follows public GitHub stars and recorded momentum—not vendor marketing. Compare projects side by side, then confirm license fit, migration effort, and operational ownership before adopting any option.
Strongest repository-activity signal: Rocket.Chat · Jump to ranking · 45.8K stars
Proprietary workplace chat and meetings suite.
Visit Microsoft TeamsCompare capabilities, licensing, and ownership model. Stars help with discovery; they are not a security or product-fit guarantee.
The Secure CommsOS™ for mission-critical operations
The Secure CommsOS™ for mission-critical operations Review the official repository, license, release activity, and deployment documentation before production adoption.
Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..
Mattermost is an open source platform for secure collaboration across the entire software development lifecycle.. Review the official repository, license, release activity, and dep
Open-source alternative to Microsoft Teams
A safe home for all your data
NextCloud is an open source software for synchronisation and file sharing for everyone, by users using the server NextCloud free of charge in the privacy of your home, to large com
Jitsi Meet - Secure, Simple and Scalable Video Conferences that you use as a standalone app or embed in your web application.
Jitsi Meet - Secure, Simple and Scalable Video Conferences that you use as a standalone app or embed in your web application. Review the official repository, license, release activ
A glossy Matrix collaboration client for the web.
A glossy Matrix collaboration client for the web. Review the official repository, license, release activity, and deployment documentation before production adoption.
Open-source alternative to Microsoft Teams
A collaborative web application (virtual office) presented as a 16-bit RPG video game
A collaborative web application (virtual office) presented as a 16-bit RPG video game Review the official repository, license, release activity, and deployment documentation before
Open-source alternative to Microsoft Teams
Open-source and local-first Slack and Notion alternative that puts you in control of your data
Open-source and local-first Slack and Notion alternative that puts you in control of your data Review the official repository, license, release activity, and deployment documentati
Open-source alternative to Microsoft Teams
Super simple group chat, without a subscription
Super simple group chat, without a subscription Review the official repository, license, release activity, and deployment documentation before production adoption.
Open-source alternative to Microsoft Teams
Yet another matrix client
Yet another matrix client Review the official repository, license, release activity, and deployment documentation before production adoption.
Open-source alternative to Microsoft Teams
:wavy_dash: Overview of the open source code for Wire
:wavy_dash: Overview of the open source code for Wire Review the official repository, license, release activity, and deployment documentation before production adoption.
Open-source alternative to Microsoft Teams
Modern email for teams and professionals. A replacement for outdated email technology and tools. Alt to hey.com, front.com, missiveapp.com
Modern email for teams and professionals. A replacement for outdated email technology and tools. Alt to hey.com, front.com, missiveapp.com Review the official repository, license,
Open-source alternative to Microsoft Teams
Mezon is a new way to communicate with your team. It's faster, better organized, better for WFH.
Mezon is a new way to communicate with your team. It's faster, better organized, better for WFH. Review the official repository, license, release activity, and deployment documenta
Open-source alternative to Microsoft Teams
Privacy-first self-hosted team chat with channels, SSO options, and voice/video via LiveKit in a compact Go binary.
Chatto is a 2026 open-source Slack/Discord-style chat you can self-host as a single binary (or Docker Compose with NATS and LiveKit). Pilot moderation, mobile notifications, and vo
Open-source alternative to Microsoft Teams
A multi-platform (Flutter) application for connecting to Matrix - an open network for secure, decentralized communication, with your favorite devices.
A multi-platform (Flutter) application for connecting to Matrix - an open network for secure, decentralized communication, with your favorite devices. Review the official repositor
Open-source alternative to Microsoft Teams
SAMA - Simple but Advanced Messaging Alternative chat server, powered by uWebsockets.js
SAMA - Simple but Advanced Messaging Alternative chat server, powered by uWebsockets.js Review the official repository, license, release activity, and deployment documentation befo
Map must-have capabilitiesList the workflows in Microsoft Teams you cannot drop during migration.
Verify the licenseConfirm it fits your use, distribution, and compliance model. Browse license briefs.
Run a proof of conceptTest real data, integrations, clients, and failure modes. Use Compare for side-by-side checks.
Plan ownershipAssess upgrades, backups, support, and an exit path. Read when self-hosting is worth it.
OpenSourceChoice currently lists 15 projects with an explicit alternative relationship to Microsoft Teams. Catalog highlights include Rocket.Chat, Mattermost, and NextCloud Server. Rankings follow public GitHub stars and recorded momentum—not paid placement. Match capabilities and license fit to your workflow before adopting any option.
Most catalogued alternatives publish source under OSI or source-available licenses and are free to inspect. Hosting, commercial support, or cloud model APIs may still cost money. Always read the project license for your use case.
5 options in this list carry a self-hosting signal. Confirm the official install guide, backups, upgrades, and hardening steps before production.
Map must-have Microsoft Teams workflows, verify license and compliance fit, run a proof of concept with real data and integrations, then plan ownership for upgrades, backups, support, and an exit path.
Narrow the same alternatives by search, license, tags, or self-hosting signals when you need a tighter shortlist.
BrazilLicense not declaredThe Secure CommsOS™ for mission-critical operations
InfrastructureOpen-source projects grouped in this category for discovery and comparison.#
TypeScriptProjects tagged with this topic in the verified catalog.
Github ActionsProjects tagged with this topic in the verified catalog.
JavaScriptProjects tagged with this topic in the verified catalog.
Microsoft TeamsProprietary workplace chat and meetings suite.
United StatesLicense not declaredMattermost is an open source platform for secure collaboration across the entire software development lifecycle..
InfrastructureOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Microsoft TeamsProprietary workplace chat and meetings suite.
GermanyAGPL-3.0-onlyA safe home for all your data
Content & CollaborationOpen-source projects grouped in this category for discovery and comparison.#
PHPProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.
LinuxDocumented runtime or deployment platform for this open-source project.Microsoft TeamsProprietary workplace chat and meetings suite.United StatesApache-2.0Jitsi Meet - Secure, Simple and Scalable Video Conferences that you use as a standalone app or embed in your web application.
Content & CollaborationOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Microsoft TeamsProprietary workplace chat and meetings suite.
United KingdomAGPL-3.0A glossy Matrix collaboration client for the web.
InfrastructureOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Microsoft TeamsProprietary workplace chat and meetings suite.A collaborative web application (virtual office) presented as a 16-bit RPG video game
InfrastructureOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Microsoft TeamsProprietary workplace chat and meetings suite.Open-source and local-first Slack and Notion alternative that puts you in control of your data
ProductivityOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Self-hostedThis project carries a self-hosting or local-deployment signal. Verify the official install guide before production use.Microsoft TeamsProprietary workplace chat and meetings suite.Super simple group chat, without a subscription
Data & AnalyticsOpen-source projects grouped in this category for discovery and comparison.#
RubyProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Self-hostedThis project carries a self-hosting or local-deployment signal. Verify the official install guide before production use.Microsoft TeamsProprietary workplace chat and meetings suite.Yet another matrix client
InfrastructureOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Microsoft TeamsProprietary workplace chat and meetings suite.:wavy_dash: Overview of the open source code for Wire
Modern email for teams and professionals. A replacement for outdated email technology and tools. Alt to hey.com, front.com, missiveapp.com
InfrastructureOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Self-hostedThis project carries a self-hosting or local-deployment signal. Verify the official install guide before production use.Microsoft TeamsProprietary workplace chat and meetings suite.Mezon is a new way to communicate with your team. It's faster, better organized, better for WFH.
Content & CollaborationOpen-source projects grouped in this category for discovery and comparison.#TypeScriptProjects tagged with this topic in the verified catalog.Github ActionsProjects tagged with this topic in the verified catalog.JavaScriptProjects tagged with this topic in the verified catalog.Microsoft TeamsProprietary workplace chat and meetings suite.
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