
Slack
Rocket.Chat
Discord
Element.io
Telegram
Zulip
Microsoft Teams
Mattermost is an open source alternative to Slack.

Which is more popular?
Based on our record, Mattermost seems to be more popular. It has been mentioned 75 times since March 2021.
Website, pricing, platforms and company facts side by side.
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|---|---|---|
| Website | mattermost.com | shadowgit.com |
| Pricing | ||
| Platforms | — | |
| Company | Startup from the United States | Startup from Germany · 1 - 9 employees · 2025 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Mattermost yet.
Every change saved. Any version restorable. AI can search what changed to debug faster. Never lose work again. Cut debugging time by 80%. Save 50% on AI tokens. 100% local.
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
Mattermost is recommended for organizations that prioritize data privacy and security, need extensive customization options, or are looking to integrate a collaboration tool into existing systems. It is also suitable for teams in regulated industries requiring on-premises solutions.
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Mattermost and ShadowGit.
ShadowGit's answer:
ShadowGit is the only tool where AI assistants can directly search your code history to debug faster while using 50% fewer tokens. Auto-captures every change without touching your main git repo. Built specifically for AI-assisted development.
ShadowGit's answer:
Electron is the primary technology being used.
ShadowGit's answer:
ShadowGit is the only tool built specifically for developers using AI. Unlike generic backup tools, your AI can actually search the history to debug faster and use 50% fewer tokens. Separate shadow repo means your main git stays clean. 100% local.
ShadowGit's answer:
AI-Accelerated solo developers that use AI coding assistants daily (Claude, Cursor, Copilot), experienced enough to feel the pain (2-10 years of coding) and that want to move fast, ship often and experiment constantly.
ShadowGit's answer:
I built ShadowGit after losing 3 hours of work to a bad AI refactor. Started as a personal backup tool, but when I added MCP integration so AI could search the history, debugging time dropped 80%. Had to share it.
Share your experience with using Mattermost and ShadowGit. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


Mattermost is an open-source platform that enables safe collaboration in self-hosted chat programs featuring file sharing, search, and integrations; groups and businesses can use it as an internal chat.
Mattermost uses monolithic architecture, which is tightly coupled and complex to understand. It restricts the scalability of the collaboration tool, which is a limitation for growing businesses. In that case,...
Below is a curated list of the 12 best self-hosted messaging apps like MirrorFly, Mattermost, Zulio, Nextcloud, and Rocket.chat that offer unique collaboration features and lets you take full control of your data.
We have no reviews of ShadowGit yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


The amazing thing is that there is almost always an open-source alternative that is 10x better in many ways, in the case of slack https://mattermost.com/ I'm looking forward for AI to make it very easy to deploy your own tools and walk... - Source: Hacker News / 24 days ago
How does it compare to MatterMost [1]? [1] https://mattermost.com/. - Source: Hacker News / 4 months ago
Slack's value is real, especially for cross-company conversations with clients and vendors. But for internal communication in companies that care about data residency or audit requirements, Mattermost is a credible self-hosted... - Source: dev.to / 5 months ago
Tracking ShadowGit since Sep 2025.
When comparing Mattermost and ShadowGit, you can also consider the following products.

A messaging app for teams who see through the Earth!
Compare Slack to Mattermost or ShadowGit:

Git is a free and open source version control system designed to handle everything from small to very large projects with speed and efficiency. It is easy to learn and lightweight with lighting fast performance that outclasses competitors.
Compare Git to Mattermost or ShadowGit:

Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.
Compare Rocket.Chat to Mattermost or ShadowGit:

Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.
Compare Discord to Mattermost or ShadowGit:

Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.
Compare Element.io to Mattermost or ShadowGit:

Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Compare Telegram to Mattermost or ShadowGit: