# Claude outage on 23 October 2026

> On 23 October, Claude had a critical outage with elevated errors on requests to Claude Fable 5.1, Sonnet 5.5 and Haiku 5.5, and on fast mode requests to Opus 5.5. claude.ai, the Claude API, Claude Code and Claude Cowork were affected. The status page incident was open from 23:37 to 00:11 on 24 October, but its final update put the impact window at 23:28 to 23:59, starting before the incident was opened. The status page said a cause had been identified but did not describe it. Cursor, GitHub, Asana, OpenAI and other services also reported problems around the same time.

- Service: [Claude](https://stackpulse.app/services/claude.md)
- Severity: critical
- Title on the status page: Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5
- Started: 2026-10-23 23:39 UTC
- Ended: 2026-10-24 00:12 UTC
- Lasted: 33 min
- Incident open on the status page: 23:37–00:11 UTC
- The status page's incident: https://stspg.io/gqp288t3qzpt
- Page: https://stackpulse.app/services/claude/outages/2026-10-23-2339

## What broke when (UTC)

| Component | Status | From | To |
|---|---|---|---|
| claude.ai | major outage | 2026-10-23 23:37 | 2026-10-23 23:54 |
| claude.ai | degraded performance | 2026-10-23 23:54 | 2026-10-24 00:11 |
| Claude API (api.anthropic.com) | major outage | 2026-10-23 23:37 | 2026-10-23 23:54 |
| Claude API (api.anthropic.com) | degraded performance | 2026-10-23 23:54 | 2026-10-24 00:11 |
| Claude Code | major outage | 2026-10-23 23:37 | 2026-10-23 23:54 |
| Claude Code | degraded performance | 2026-10-23 23:54 | 2026-10-24 00:11 |
| Claude Cowork | major outage | 2026-10-23 23:37 | 2026-10-23 23:54 |
| Claude Cowork | degraded performance | 2026-10-23 23:54 | 2026-10-24 00:11 |

## At the same time

- [Musixmatch](https://stackpulse.app/services/musixmatch.md): issue from 2026-10-23 22:47 UTC
- [OpenAI](https://stackpulse.app/services/openai.md): issue from 2026-10-23 22:53 UTC
- [Edmentum](https://stackpulse.app/services/edmentum.md): issue from 2026-10-23 23:07 UTC
- [Archive of Our Own](https://stackpulse.app/services/archive-of-our-own.md): issue from 2026-10-23 23:15 UTC
- [Cursor](https://stackpulse.app/services/cursor.md): major_outage from 2026-10-23 23:40 UTC
- [GitHub](https://stackpulse.app/services/github.md): issue from 2026-10-23 23:42 UTC
- [Asana](https://stackpulse.app/services/asana.md): major_outage from 2026-10-23 23:57 UTC

Problems at the same time are a clue, never proof that one caused another.

Stackpulse isn't affiliated with Claude.