HighDeprecation
Claude retires 1M-token context window beta; migrate to Sonnet 4.6 or Opus 4.6
Action Required
Applications relying on the 1M-token context window in Claude Sonnet 4.5 will fail for requests >200k tokens; migrate to Sonnet 4.6 or Opus 4.6 to retain long-context support and avoid errors.
AI Impact Summary
Claude has retired the 1M-token context window beta for Sonnet 4.5 and 4, enforcing a hard 200k token limit. Requests exceeding 200k tokens will error until migration to a supported model. To preserve long-context capability, upgrade to Claude Sonnet 4.6 or Claude Opus 4.6 (GA with standard pricing), update clients to the new endpoints, and validate downstream tooling and cost implications for larger contexts.
Claude retires 1M-token context window beta; migrate to Sonnet 4.6 or Opus 4.6
Affected Systems
Claude Sonnet 4.5
- Date
- Date not specified
- Change type
- deprecation
- Severity
- high