Claude Opus 4.1 (retired)
Claude Opus 4.1 is an Anthropic model that was retired on August 5, 2026.
- Lab
- Anthropic
- Release date
- Status
- Retired
- API model ID
- claude-opus-4-1-20250805
- Shutdown date
Anthropic retired Claude Opus 4.1 (claude-opus-4-1-20250805) on August 5, 2026, after announcing the deprecation on June 5, 2026; requests to it now return an error. Anthropic recommends upgrading to Claude Opus 5, and researchers can request access through its External Researcher Access Program.
- Availability
- Retired; requests return an error. Recommended replacement: Claude Opus 5. Researcher access via the External Researcher Access Program.
- Official source
- platform.claude.com
- Last checked
Questions
When was Claude Opus 4.1 retired?
Anthropic retired Claude Opus 4.1 on August 5, 2026, after announcing the deprecation on June 5, 2026.
Can I still use Claude Opus 4.1?
No. Requests to
claude-opus-4-1-20250805 now return an error; researchers can request access through the External Researcher Access Program.What replaces Claude Opus 4.1?
Anthropic recommends upgrading to Claude Opus 5.
Source
Release dates, model IDs and limits come from each lab’s own announcement, changelog, documentation or deprecations page, linked on every model with the date it was last checked. How we pick and check sources: editorial standards.