Team Chat Apps · reliability comparison
Slack vs Zulip: which is more reliable? (2026)
Zulip is more reliable than Slack, scoring 100.0 vs 41.6 out of 100. Over the last 90 days Slack reported 8 incidents and Zulip reported 0, with effective uptime of 97.89% and 100% respectively.
Data updated Nov 1, 2026 · How we score
| Metric | Slack | Zulip |
|---|---|---|
| Reliability score | 41.6 | 100.0 |
| Rank (team chat apps) | #11 | #5 |
| Uptime (90 days) | 97.89% | 100% |
| Incidents (90 days) | 8 | 0 |
| Partial / major outages | 4 | 0 |
| Avg time to resolve | 15h 28m | — |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Slack and Zulip differ
- Zulip reported no incidents in the last 90 days, while Slack reported 8.
- Slack had 4 partial or major outages, compared with 0 for Zulip.
- Slack's longest outage on record lasted 3d (Aug 13, 2026); Zulip's lasted 3h 55m (Mar 26, 2026).
90-day uptime
Slack
Zulip
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
Recent Slack incidents
- Degraded performanceOct 22, 2026 · resolved (duration not published)
- Degraded performanceOct 14, 2026 · resolved in 6m
- Degraded performanceOct 9, 2026 · resolved (duration not published)
Incident: Slack for iOS closing unexpectedly when opening channels
- Partial outageOct 1, 2026 · resolved in 6h 20m
Incident: Free Plan Customers Are Experiencing Message Failures
- Partial outageSep 12, 2026 · resolved in 8h 56m
Incident: Some customers experiencing blurry image previews and download issues
- Degraded performanceSep 10, 2026 · resolved in 2h 40m
Incident: Trouble loading Workspace-level Apps & Workflows settings page is returning blank pages
Recent Zulip incidents
No incidents reported by Zulip in the last 90 days.
Other team chat apps to consider
- Element · #1 · 100% uptime
- Flock · #2 · 100% uptime
- Mattermost · #3 · 100% uptime
- Twist · #4 · 100% uptime