Best Slack alternatives in 2026

Slack is a channel-based messaging platform built for workplace communication and collaboration. Acquired by Salesforce, it serves as a central hub where teams organize conversations by topic, project, or department in dedicated channels.

Here are the real cost and limitation gotchas that push teams to look elsewhere:

• • 90-day message history on Free: after 90 days, old messages become invisible (not deleted, they return if you upgrade). This is the most common upgrade trigger and feels coercive for teams that relied on older unlimited history
• • 10 app integration limit on Free: most teams use 15-30 integrations (GitHub, Google Calendar, Zoom, Jira, etc.). Hitting the 10-app cap happens within the first week for technical teams
• • Per-user billing for inactive users: Slack charges for every user in the workspace, including those who rarely log in. A 100-person company where 30 people use Slack monthly still pays for 100 seats. Slack offers 'fair billing' (credits for inactive users after 14+ days) but only on annual plans
• • Slack AI is tier-gated: basic AI (summaries, huddle notes) requires Pro. Advanced AI (search, recaps, translations) requires Business+ at $15/user/mo. There is no way to add AI to Pro without upgrading the entire workspace

The 9 alternatives below cover the same core job (communication) with different trade-offs.