Claude Opus 4.8
Language modelPrevious generationCard summarizedBuilds on Opus 4.7 with improvements across benchmarks, and is a more effective collaborator
Active (legacy) · retires not before 28 May 2027● Re-checked 12 Oct 2026 · 155 facts · 0 corrections · 2 unconfirmedSource: System Card: Claude Opus 4.8 (246 pp)
Use it via API
Where to call it
- Claude API
claude-opus-4-8 - Amazon Bedrock
anthropic.claude-opus-4-8 - Google Vertex AI
claude-opus-4-8 - Microsoft Foundry / Azure
claude-opus-4-8
Supports
- Image input
- PDF input
- Structured outputs
- Reasoning control
- Tool calling
- Web search
- Prompt caching
- Batch API
Good for
- Software engineering (SWE-bench Verified 88.6%, SWE-bench Pro 69.2%)
- Agentic tool use and agentic search
- Knowledge work and real-world professional tasks (GDPval-AA, Finance Agent)
Watch out for
Replaced by
Claude Opus 5.5$4.00 / $20.00
This model: $5.00 / $25.00 per 1M tokens
Compare side by sideOverview
Opus 4.8
Builds on Opus 4.7 with improvements across benchmarks, and is a more effective collaborator
- Cost
- $5.00 in
- Context
- 1M
- Input / output
- $5.00 / $25.00
- Max output
- 128K
- Knows up to
- January 2026
- Released
- 28 May 2026
An upgrade on Claude Opus 4.7 with better software engineering, agentic tool use and knowledge work; Anthropic's most capable general-access model at release. It does not advance the capability frontier beyond Claude Mythos Preview. p.3, p.11
claude-opus-4-8- Input / output per 1M
- $5.00 / $25.00
- Context window
- 1M
- Max output
- 128K
- Knows up to
- January 2026
- Reasoning
- Adaptive
- Weights
- Closed
About this card. A model card is the maker's own account of a model: what it's for, how it was trained and tested, and where it falls short. This page condenses Anthropic's System Card: Claude Opus 4.8. Every claim carries its source page.