Inline vs Mattermost: Pricing and Ratings Compared (2026)
Entry prices and free plans as read on each vendor's pricing page, and user ratings as published on review sites, for Inline and Mattermost side by side. This page compares data; it is not a hands-on review.
On the data: On the data below the two are close or not directly comparable, so we do not name a winner for this pair.
Short on time? Here's the quick answer
Based on published vendor pricing and features and on public review data, here's who should pick what:
Inline
Collaborate with humans and AI in threaded conversations
Best for you if:
- • You want a fully free tool (Mattermost requires payment)
Mattermost
Open-source team collaboration platform
Best for you if:
- • You want open source Slack alternative
| At a Glance | Inline | Mattermost |
|---|---|---|
Starts at | Free 100% free | Free plan, paid from $10/user/mo, billed monthly Professional plan |
Category | Communication Team Chat | Communication Team Chat |
Rating | n/a | 4.3/5 G2 4.3 · Capterra 4.4 · SourceForge 4.3 604 reviews |
Free plan | Yes | Yes |
Choose Inline or Mattermost?
Choose Inline if
- You want a fully free tool (Mattermost requires payment)
- You want thread-based structure keeps conversations organized and searchable
- You want combines human and AI agent collaboration in one place
Choose Mattermost if
- You want open source Slack alternative
- You want self-hostable
In-Depth Analysis
Inline
Collaborate with humans and AI in threaded conversations
Strengths
- Pro: Thread-based structure keeps conversations organized and searchable
- Pro: Combines human and AI agent collaboration in one place
- Pro: Offers CLI and plugin extensibility for technical teams
Weaknesses
- Con: Limited to macOS and iOS beta versions
- Con: No web version or Windows/Linux support yet
Key features
Mattermost
Open-source team collaboration platform
Mattermost's pricing is fair, offering a generous Free tier for small teams.
Strengths
- Pro: Open source Slack alternative
- Pro: Self-hostable
- Pro: Good for compliance
- Pro: No per-user cloud cost
- Pro: Customizable
Weaknesses
- Con: Less polished than Slack
- Con: Smaller integration library
- Con: Self-hosting required for best value
- Con: Learning curve
- Con: Community smaller
Key features
Plans and prices: Inline vs Mattermost
| Tool | Plans and prices | Source |
|---|---|---|
| Inline | No plan prices on file | inline.chat |
| Mattermost |
| mattermost.com/pricing read Sep 30, 2026 |
Prices as read on each vendor's own pricing page on the date shown. Plans are listed per tool and are not matched against the other tool's plans: a plan name or price in one column says nothing about the same row in the other. Details on Inline pricing and Mattermost pricing.
Key Takeaways
Inline
- Choose if you want collaborate with humans and AI in threaded conversations
Mattermost
- Choose if you want open-source team collaboration platform
What the data shows
On the data below the two are close or not directly comparable, so we do not name a winner for this pair.
- Only Mattermost has a published user rating (4.3/5 from 604 reviews); Inline has none we can show.
- Mattermost starts at $10/user/mo, billed monthly; Inline has no public paid plan price on file.
- Both have a free plan.
Criteria: user rating (only above 20 reviews on both sides, gap of 0.2 or more), entry price (only on the same billing basis), free plan. How we rate
Frequently Asked Questions
How do Inline and Mattermost compare in 2026?
On the data below the two are close or not directly comparable, so we do not name a winner for this pair. Only Mattermost has a published user rating (4.3/5 from 604 reviews); Inline has none we can show. Mattermost starts at $10/user/mo, billed monthly; Inline has no public paid plan price on file. Both have a free plan.
What are Inline and Mattermost used for?
Inline: Collaborate with humans and AI in threaded conversations. Mattermost: Open-source team collaboration platform.
What does Inline cost vs Mattermost?
Inline is free. Mattermost's cheapest paid plan is Professional at $10/user/mo, billed monthly; it also has a free plan. Prices read on the vendors' pricing pages, latest check Sep 30, 2026.
What's the main difference between Inline and Mattermost?
Inline's main strength: thread-based structure keeps conversations organized and searchable. Mattermost's main strength: open source Slack alternative.