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

Substack
Formo.so
Advanced analytics for Substack writers. Runs 100% locally, no cloud, no subscription. Discover your superfans, churn risk, and cohort retention.
Which is more popular?
Based on our record, Mattermost seems to be a lot more popular than StackStats.app. While we know about 76 links to Mattermost, we've tracked only 1 mention of StackStats.app.
Website, pricing, platforms and company facts side by side.
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| Website | mattermost.com | stackstats.app |
| Pricing | ||
| Company | Startup from the United States | Startup from the United Arab Emirates · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Mattermost yet.
StackStats is a local desktop app for serious Substack writers. Import your CSV exports and get analytics Substack doesn't show you: bot-filtered open rates, cohort retention, dead subscriber detection, superfan ID, content-to-growth correlation, and an optional AI layer (supports Ollama,...
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
No StackStats.app videos yet. You could help us improve this page by suggesting one.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Mattermost and StackStats.app.
StackStats.app's answer:
I built StackStats because Substack's native analytics weren't cutting it. I wanted cohort data, real open rates (not bot-inflated), and a way to identify which posts were actually driving subscriber growth — but every tool I found was either cloud-based or required migrating off Substack entirely. So I built a local app that works with Substack's own CSV exports. No migration, no cloud, no subscription.
StackStats.app's answer:
StackStats runs 100% locally on your machine — your subscriber data never touches a server. It also goes far beyond what Substack shows natively: bot-filtered open rates, cohort retention, superfan identification, dead subscriber detection, and content-to-growth correlation. No subscription, no account, no cloud. Pay once, own it forever.
StackStats.app's answer:
Most newsletter analytics tools are cloud-based SaaS with monthly subscriptions. StackStats is a one-time purchase that runs entirely on your device. For Substack writers who care about privacy — especially those with paid subscribers — that's a meaningful difference. You also get analytics features that don't exist anywhere else, like bot-filtered open rates and cohort retention, without having to migrate away from Substack.
StackStats.app's answer:
Serious Substack writers who are frustrated by Substack's shallow native analytics and want real data to drive growth — without moving their subscriber data to the cloud.
StackStats.app's answer:
Electron (macOS + Windows), HTML/CSS/JavaScript, Chart.js, PapaParse. Optional AI layer supports Ollama, Claude, GPT-4, Gemini, Groq, and OpenRouter. Licensing via Cloudflare Workers + D1. Payments via Gumroad.
Share your experience with using Mattermost and StackStats.app. 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 StackStats.app 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 / about 1 month 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 / 3 months ago
How does it compare to MatterMost [1]? [1] https://mattermost.com/. - Source: Hacker News / 6 months ago
I'm working on 3 products now: 1. FormBeep(https://formbeep.com) at $38 MRR now - A form to Whatsapp tool. Stack is mainly CF workers with Clerk Auth. 2. SlashLink(https://slashlink.app) $0 - A simple pay as you go amazon link localizer.... - Source: Hacker News / 2 days ago
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