Sonnet 4.6 saw elevated errors on April 9, 2026
This was a model-layer event. It reinforces the pattern that Claude reliability problems often sit inside one model family instead of looking like one monolithic outage.
Published: Apr 9, 2026, 4:07 AM EDT
Updated: Apr 21, 2026, 8:40 AM EDT
Incident started: Apr 9, 2026, 4:07 AM EDT
Crowd spike noticed: Apr 9, 2026, 4:12 AM EDT
Resolved: Apr 9, 2026, 4:53 AM EDT
Affected surface: Claude Sonnet 4.6 requests
Official updates said Sonnet 4.6 was seeing elevated error rates until the model returned to normal later that morning.
- The problem looked concentrated in one model family rather than all Claude products failing together.
- Developers tied to Sonnet 4.6 would feel this incident more sharply than general Claude web users.
- It fits the broader archive pattern that model instability deserves separate treatment from login and upload failures.
A reviewed note on the April 9, 2026 Sonnet 4.6 incident affecting model reliability rather than every Claude surface together.
Review the methodology page for how crowd reports are deduplicated and the status lag explainer for how independent reports differ from provider updates.
If you want the broader archive context, go back to the Claude outage history page.
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