HighDeprecation
Claude retiring 1M-token context window for Sonnet 4.5/4; migrate to Sonnet 4.6 or Opus 4.6
Action Required
Applications relying on 1M-token context in Claude Sonnet 4.5/4 will fail for inputs >200k tokens unless migrated to Claude Sonnet 4.6 or Claude Opus 4.6 to preserve 1M-context support.
AI Impact Summary
The 1M-token context window beta for Claude Sonnet 4.5/4 has been retired; requests with inputs exceeding 200k tokens now error. This affects long-context use cases such as large documents, extensive chat histories, or prompts that previously leveraged the 1M window. To retain 1M-context capabilities, migrate to Claude Sonnet 4.6 or Claude Opus 4.6 and adjust ingestion/prompting workflows to route oversized prompts accordingly.
Claude retiring 1M-token context window for Sonnet 4.5/4; migrate to Sonnet 4.6 or Opus 4.6
Affected Systems
Claude Sonnet 4.5
- Date
- Date not specified
- Change type
- deprecation
- Severity
- high