Best Slack alternatives in 2026
The best Slack alternatives in 2026 are Mattermost, Microsoft Teams, Rocket.Chat. Mattermost is the strongest free option. Microsoft 365 costs less, from $1.99/mo versus $8.75/mo for Slack.
Why people look for Slack alternatives
Slack is used by teams of every size for channel-based messaging and is known for its large integration ecosystem. Per-seat pricing from $8.75 gets expensive for large teams, the free plan shows only 90 days of history, and since August 2024 Slack deletes free-workspace messages and files older than one year.
In June 2025 Slack also raised the Business+ price while bundling more AI into it. When choosing a replacement, weigh per-seat cost, history and data retention, self-hosting or compliance needs, and whether you already pay for Microsoft 365 or Google Workspace.
- Expensive per seat for large teams
- Free plan's 90-day history limit
- Notification overload without discipline
- Slack AI costs extra below Business+
- Slack starts at $8.75/mo (Freemium).
Best Slack alternative by need
| # | Tool | Pricing | Starts at | Best for | Platforms | Votes |
|---|---|---|---|---|---|---|
| 1 | Mattermost Self-hosted secure collaboration | Open source | $0 | Enterprise, Developers | web, macos, windows, linux, ios, android | 0 |
| 2 | Microsoft Teams Microsoft's chat, meetings and calling hub inside Microsoft 365 | Freemium | $4/mo | Enterprise, Small businesses | web, macos, windows, ios, android | 0 |
| 3 | Rocket.Chat Open-source team chat and omnichannel | Open source | $0 | Enterprise, Developers | web, macos, windows, ios, android | 0 |
| 4 | BAND Shared chat rooms where AI agents and people coordinate work | Freemium | $18/mo | Developers, Enterprise | web, macos, windows, linux, android | 0 |
| 5 | Discord Voice, video and text communities | Freemium | $3/mo | Creators, Developers | web, macos, windows, linux, ios, android | 0 |
| 6 | Microsoft 365 Word, Excel, Outlook, Teams and OneDrive in one subscription | Freemium | $2/mo | Small businesses, Enterprise, Freelancers | web, windows, macos, ios, android | 0 |
| 7 | Twist Async-first team communication | Freemium | $8/mo | Small businesses | web, macos, windows, ios, android | 0 |
| 8 | Zoom Video meetings that became a verb | Freemium | $17/mo | Small businesses, Enterprise | web, macos, windows, ios, android | 0 |
| 9 | Google Meet Video calls inside Google Workspace | Freemium | $8/mo | Small businesses, Enterprise | web, ios, android | 0 |
| 10 | agentmash Shared room that warns coding agents before they edit the same file | Freemium | $20/mo | Developers, Small businesses, Enterprise | macos, windows, linux | 0 |
10 Slack alternatives compared
- 1
Mattermost
Self-hosted secure collaboration
Why pick it over Slack: Mattermost is open source and can be self-hosted, so organizations with strict security or data residency rules keep team chat on their own infrastructure, which Slack's cloud service does not offer.
- 2
Microsoft Teams
Microsoft's chat, meetings and calling hub inside Microsoft 365
Why pick it over Slack: Microsoft Teams starts at $4 per user against Slack's $8.75 and is available bundled with Microsoft 365 business plans, so organizations already on Microsoft 365 get chat, meetings and files without paying twice.
- 3
Rocket.Chat
Open-source team chat and omnichannel
Why pick it over Slack: Rocket.Chat is open source and adds omnichannel customer messaging to team chat, so organizations that want self-hosting plus customer conversations in one tool get both, while Slack focuses on internal chat.
- 4
BAND
Shared chat rooms where AI agents and people coordinate work
Best for: Developers and engineering leaders who run several AI agents at once and need one place to coordinate and audit them.
- 5
Discord
Voice, video and text communities
Why pick it over Slack: Discord servers are free, with optional paid upgrades from $2.99, so communities, creators and developer relations teams get voice, video and text chat without Slack's per-seat cost or free-plan history limits.
- 6
Microsoft 365
Word, Excel, Outlook, Teams and OneDrive in one subscription
Why pick it over Slack: Microsoft 365 business plans bundle Teams with Word, Excel, Outlook and OneDrive, so companies that already rely on Office apps can replace Slack inside one Microsoft subscription and admin console.
- 7
Twist
Async-first team communication
Why pick it over Slack: Twist starts at $8, slightly below Slack's $8.75, and organizes conversations into threads for asynchronous work, so remote teams tired of Slack's real-time notification load get a calmer way to communicate.
- 8
Zoom
Video meetings that became a verb
Why pick it over Slack: Zoom starts at $16.99 and centers on reliable video meetings with team chat included, so organizations whose work happens mostly on calls, often with outside guests, may get more from it than from Slack's huddles.
- 9
Google Meet
Video calls inside Google Workspace
Why pick it over Slack: Google Meet comes with Google Workspace from $8.40, which also includes Google Chat, so teams already on Workspace can cover meetings and messaging without paying for a separate Slack subscription.
- 10
agentmash
Shared room that warns coding agents before they edit the same file
Best for: Engineering teams where several developers run AI coding agents on the same repository at once.
Slack alternatives: FAQ
What is the best alternative to Slack?
Based on features, audience and market presence, the strongest Slack alternatives are Mattermost, Microsoft Teams, Rocket.Chat. Mattermost is the closest match for most teams.
Is there a free alternative to Slack?
Yes. Mattermost can be used for free. Other free or freemium alternatives to Slack include Microsoft Teams, Rocket.Chat, BAND.
What is cheaper than Slack?
Microsoft 365 starts at $1.99/mo, while Slack starts at $8.75/mo. Prices are checked on each vendor's own pricing page.
Is there an open-source alternative to Slack?
Yes. Mattermost is open source, so you can self-host it or inspect the code.