Elevated errors on Sonnet 4, Sonnet 4.5 and Haiku 4.5

Incident Report for Claude

Resolved

As of 3:55 PT / 11:55 UTC the level of errors on Sonnet 4.0 has returned to normal.
Posted Nov 20, 2025 - 12:03 UTC

Monitoring

As of 2:14 PT / 10:14 UTC we have mitigated all errors on Sonnet 4.5. Unfortunately the error rate is still higher than baseline for Sonnet 4.0, but we have implemented a fix and it should go down in the next few minutes.
Posted Nov 20, 2025 - 11:03 UTC

Update

We are continuing to work on a fix for this issue.
Posted Nov 20, 2025 - 10:15 UTC

Identified

The issue has been identified and a fix is being implemented.
Posted Nov 20, 2025 - 09:10 UTC

Update

We are continuing to investigate this issue.
Posted Nov 20, 2025 - 08:20 UTC

Investigating

We are currently investigating this issue.
Posted Nov 20, 2025 - 08:10 UTC
This incident affected: claude.ai, platform.claude.com (formerly console.anthropic.com), Claude API (api.anthropic.com), and Claude Code.