Is Claude down? › Outage history › Sep 3, 2026
Claude partial outage on Sep 3, 2026: what happened
On Sep 3, 2026, the Claude status page reported "Elevated errors for multiple models". About 2 hours 57 min: from Sep 3, 2026, 13:26 UTC to Sep 3, 2026, 16:23 UTC, by the official start and resolution times.
Claude right now
At our last refresh (Oct 22, 2026, 12:35 UTC) Claude was up: All Systems Operational.
- Started
- Sep 3, 2026, 13:26 UTC
- Resolved
- Sep 3, 2026, 16:23 UTC
- Duration
- 2 hours 57 min
- Official impact
- Major
- Affected
- claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork
- Source
- Elevated errors for multiple models on the Claude status page
The Claude status page rated the impact "Major": a partial outage. Some parts or some users were affected; it was not a complete outage.
What caused the Claude partial outage?
The Claude status page has not published a cause. When it identified the problem at 13:41 UTC on Sep 3, 2026, it said: "We have identified the cause of elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and are working on a fix. We will provide an update as soon as possible."
When was it fixed?
The Claude status page marked it resolved at Sep 3, 2026, 16:23 UTC, 2 hours 57 min after it started. A fix was in place and being monitored from Sep 3, 2026, 16:06 UTC. Its resolution note: "The issue affecting Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 has been resolved. Impact has ended as of 9:16 PT / 16:16 UTC."
Timeline of official updates
Every update the Claude status page posted, oldest first. Times are UTC.
Sep 3, 2026, 13:26 UTC investigating
We are investigating elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5. We will provide an update as soon as possible.
Sep 3, 2026, 13:41 UTC identified
We have identified the cause of elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and are working on a fix. We will provide an update as soon as possible.
Sep 3, 2026, 13:50 UTC identified
An exhaustive list of affected models: Mythos/Fable 5.1, Mythos/Fable 5, Opus 5, Opus 4.8, Opus 4.6.
Sep 3, 2026, 14:49 UTC identified
We are continuing to work on a fix for this issue.
Sep 3, 2026, 15:25 UTC identified
The only affected models right now are Opus 4.8 and Opus 5. The rest of the models have recovered to baseline error rate.
Sep 3, 2026, 16:06 UTC monitoring
A fix has been deployed for Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and we are monitoring for recovery.
Sep 3, 2026, 16:23 UTC resolved
The issue affecting Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 has been resolved. Impact has ended as of 9:16 PT / 16:16 UTC.
The same incident was listed for Claude Cowork, Claude Code, which share Claude's status page.
Claude partial outage questions
What caused the Claude partial outage on Sep 3, 2026?
The Claude status page has not published a cause. When it identified the problem (Sep 3, 2026, 13:41 UTC) it said: "We have identified the cause of elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and are working on a fix. We will provide an update as soon as possible."
When was the Claude partial outage on Sep 3, 2026 fixed?
The Claude status page marked it resolved at Sep 3, 2026, 16:23 UTC, 2 hours 57 min after it started. A fix was in place and being monitored from Sep 3, 2026, 16:06 UTC. Its resolution note: "The issue affecting Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 has been resolved. Impact has ended as of 9:16 PT / 16:16 UTC."
How long did the Claude partial outage last?
About 2 hours 57 min: from Sep 3, 2026, 13:26 UTC to Sep 3, 2026, 16:23 UTC, by the official start and resolution times.
Was Claude completely down?
No. The Claude status page rated the impact "Major": a partial outage. Some parts or some users were affected; it was not a complete outage. The affected parts listed were: claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork.
Which parts of Claude were affected?
The Claude status page listed: claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork.
Other recent Claude incidents
- Elevated errors affecting Connectors Oct 22, 2026, 03:50 UTC, 4 hours 17 min
- Degraded performance for Claude Fable 5 Oct 21, 2026, 19:49 UTC, 40 minutes
- Issue with spend limits Oct 7, 2026, 21:23 UTC, duration not stated
- Elevated errors on platform.claude.com Oct 7, 2026, 13:25 UTC, 6 days 5 hours
- Elevated errors loading usage data on platform.claude.com Oct 7, 2026, 01:20 UTC, 1 hour 13 min
- Elevated errors for Claude Opus 5.5 Oct 6, 2026, 12:24 UTC, 19 minutes
Full Claude outage history and biggest outages → · Recent outages across all services →
Quotes are the Claude status page's own words, from the official incident. Is It Up or Down is independent and not affiliated with Claude. Times are UTC.