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

The modern platform for creating, sharing, and collaborating on AI prompts. Advanced version control and real-time testing.

Which is more popular?
Based on our record, Mattermost seems to be more popular. It has been mentioned 76 times since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | mattermost.com | diffyn.com |
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| Company | Startup from the United States | — |
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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.
Mattermost - An Open Source, Self Hosted, Slack Chat Alternative
More videos
The Ultimate Prompt Tool for Creators – Visualize & Organize with Diffyn
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Mattermost and Diffyn.
Diffyn's answer:
Addresses workflow and change management on LLM prompts, provide teams with traceability and visualization of tests across multiple models, provide deeper understading into efficiency of these prompts.
Diffyn's answer:
Diffyn is the platform that specializes on both change management and multi-model analysis.
Diffyn's answer:
React, Next.js, POSTGRESQL
Diffyn's answer:
Professionals incorporating LLMs or AI tools in their workflow and wants to keep track of changes and test their prompts.
Diffyn's answer:
I started working on Diffyn when I notice that prompting has become an essential part of work across many industries. While there are version control platofrms like github, they are not designed for just prompt management are can be overkill such applications, it is also not integrated natively with various LLMs and relevant tools for users to validate ideas and visualise results properly.
Share your experience with using Mattermost and Diffyn. 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 Diffyn yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


Mattermost | Remote (US and Canada) | FT | Multiple roles Mattermost (https://mattermost.com) is an open-core collaboration and workflow automation platform for air-gapped, on-prem and private clouds. Our customers are in defense,... - Source: Hacker News / 2 days ago
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 / about 1 month ago
How does it compare to MatterMost [1]? [1] https://mattermost.com/. - Source: Hacker News / 5 months ago
Tracking Diffyn since Jun 2025.
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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.
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Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
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Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.
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