Claude outage on 27 October 2026
Major outageAn email when it goes down, and when it’s back.
“Elevated errors for Claude Sonnet 5.5”
On 27 October, Claude had a major outage with elevated errors on requests to Claude Sonnet 5.5, affecting claude.ai, the Claude API, Claude Code and Claude Cowork. The outage lasted 41 minutes, from 09:15 to 09:57 UTC, though the status page showed the components affected only from 09:14 to 09:38, when it reported a fix had been deployed and recovery was being monitored, before marking the incident resolved at 09:56. Litmus also had a major outage at the same time, starting at 08:31 UTC.
Claude’s own incident page ↗- When
- 09:15–09:57 UTC
- How long
- 41 min
- Incident open on its page
- 09:14–09:56 UTC
- Components affected
- 4
- Claude, 30 days before
- 7 other outages
What broke when
From Claude’s own status page: when it moved each component into trouble, and back.
At the same time
Started in the hour before or during it
And 80 lesser-known services. Problems at the same time are a clue, never proof that one caused another.
Timeline
Times in UTC
- Investigating
- claude.ai: partial outage
- Claude API (api.anthropic.com): partial outage
- Claude Code: partial outage
- Claude Cowork: partial outage
- Fix in place, monitoring
- claude.ai: back to normal
- Claude API (api.anthropic.com): back to normal
- Claude Code: back to normal
- Claude Cowork: back to normal
- Resolved
Where this comes from
Stackpulse reads Claude’s official status page at status.claude.com every minute. The times above are when it reported the problem; the summary is written from its updates and checked against them.
Stackpulse isn’t affiliated with Claude. Names and logos belong to their owners.