Claude (Anthropic) outage on October 23, 2026: Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5
Claude reported an incident affecting Claude (Anthropic) for 34 minutes on 23 October 2026, from 23:37 to 00:11 UTC.
Resolved
Official incident reported by Claude
- Started
- 23:37
- 23 Oct 2026 UTC
- Resolved
- 00:11
- 24 Oct 2026 UTC
- Duration
- 34m
- 34 minutes
- Impact
- Critical
- as rated by Claude
- Updates
- 4
- posted by Claude
Timeline
All times UTC.
Official incident from Claude
Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5
-
Official
Investigating
We are investigating elevated errors on requests to Claude Fable 5.1. We will provide an update as soon as possible.
-
Official
Identified
We have identified the cause of elevated errors on requests to Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5, as well as fast mode requests to Opus 5.5 and are working on a fix. We will provide an update as soon as possible.
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Official
Monitoring
We are seeing success rates return to normal for all affected models, and are continuing to monitor to ensure no further issues.
-
Official
Resolved
The issue affecting Claude models has been resolved. Impact occurred from 16:28 PT / 23:28 UTC on October 23 to 16:59 PT / 23:59 UTC on October 23.
"Official" rows are quoted from Claude's public status page, status.claude.com. Very long posts are shortened.
What our checkpoints saw
HostTracker's checkpoints, which test claude.ai from several locations, recorded no outage of 5 minutes or longer during this incident. A provider can report a problem that affects only some features, regions or accounts, which a check of the main address does not see. The live Claude (Anthropic) status shows what our checks see right now.
Does your product depend on Claude (Anthropic)?
An outage like this one reaches your users through your product, and most teams hear about it from a customer rather than from a dashboard. HostTracker watches any endpoint you name - your own site, an API you call, a vendor you resell - from 300+ locations, confirms a failure from several of them before it says anything, and then tells you by email, SMS, voice call or your chat tool.
You get the same record you are reading here for your own services: every outage timestamped, with the checks that observed it.
Independent measurement by HostTracker. Not affiliated with Claude (Anthropic). Official updates are quoted from Claude's public status page and remain Claude's own words.