Outage in Anthropic
Elevated errors for multiple models
Resolved MajorIncident Report
Summary AI Generated
Anthropic experienced elevated error rates across Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 for approximately 1.7 hours, affecting both claude.ai and api.anthropic.com. Users reported widespread API and application failures, with only the browser-based chat remaining functional during the incident. The root cause was identified and resolved, with all models returning to normal success rates by 7:10pm PT on September 22, 2026.
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.
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Latest Updates ( sorted recent to last )
RESOLVED
8 days ago - at 09/22/2026 02:35AM
This issue has been resolved. Impact occurred from 5:50pm PT / 00:50 UTC to 7:10pm PT / 02:10 UTC.
MONITORING
8 days ago - at 09/22/2026 02:11AM
We have seen success rates return to normal across affected models, and are monitoring closely to ensure no further issues.
IDENTIFIED
8 days ago - at 09/22/2026 01:35AM
We are continuing to work to resolve errors affecting some models. At this time, requests to Claude Fable 5 and 5.1 and Mythos 5 and 5.1 have returned to normal success rates. We are working to resolve remaining errors affecting Claude Opus 5, and will provide an additional update shortly.
IDENTIFIED
8 days ago - at 09/22/2026 01:17AM
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.
INVESTIGATING
8 days ago - at 09/22/2026 12:57AM
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.
Latest Anthropic outages
Elevated errors on claude.ai, Claude Code, Claude Cowork and the Claude API - about 17 hours ago
Issues with Google Play subscriptions - 14 days ago
Elevated latency on the Claude API for some users - 19 days ago
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