Claude Opus 4.8
Last Opus 4.x. Adaptive thinking only (omit thinking = no thinking); sampling params and budget_tokens removed. Fast mode $10/$50 (Claude API only). Retirement not sooner than 2027-05-28.
- Context window
- 1,000,000 tokens
- Max output
- 128,000 tokens
- Knowledge cutoff
- 2026-01
- Input
- text, image, pdf
- Output
- text
- License
- proprietary
- Pricing
- input: $5 · output: $25 · cache read: $0.5 (per 1M tokens (USD); Batch API 50% off) source
- Verified
- 2026-09-29
How to call it
| Provider | Model id | Endpoint / URL | Docs |
|---|---|---|---|
| Anthropic API (Claude API) | claude-opus-4-8 | https://api.anthropic.com/v1/messages | docs |
| AWS Bedrock (Messages API / Mantle) | anthropic.claude-opus-4-8 | — | docs |
| Google Cloud Vertex AI | claude-opus-4-8 | — | docs |
| Microsoft Foundry (Azure) | claude-opus-4-8 | — | docs |
| Claude Platform on AWS | claude-opus-4-8 | — | docs |
| OpenRouter | anthropic/claude-opus-4.8 | openrouter.ai/anthropic/claude-opus-4.8 | — |
| Web app | — | claude.ai | — |
Notable capabilities (4)
- Code honesty: About 4x less likely than Opus 4.7 to let flaws in its own code pass without comment. source
- Browser agents: Scored 84% on Online-Mind2Web, ahead of Opus 4.7 and GPT-5.5. source
- FIRST Legal agent benchmark: Anthropic says it was the first model to exceed 10% on the Legal Agent Benchmark all-pass standard. source
- Cheaper fast mode: Fast mode runs up to 2.5x faster, at a lower premium than earlier fast mode. source
Legacy; common fallback target for refusals on Claude 5 models.
curl https://api.anthropic.com/v1/messages \
-H "x-api-key: $ANTHROPIC_API_KEY" -H "anthropic-version: 2023-06-01" -H "content-type: application/json" \
-d '{"model":"claude-opus-4-8","max_tokens":16000,"messages":[{"role":"user","content":"Hello"}]}'
Sources:
- Model page: https://platform.claude.com/docs/en/models/opus-4-8/overview
- Pricing: https://platform.claude.com/docs/en/about-claude/pricing
- Models overview: https://platform.claude.com/docs/en/about-claude/models/overview
- Deprecations: https://platform.claude.com/docs/en/about-claude/model-deprecations
Other Anthropic models
Claude Sonnet 5.5 · Claude Opus 5.5 · Claude Fable 5.1 · Claude Mythos 5.1 · Claude Haiku 4.5 · Claude Opus 5 · Claude Sonnet 5 · Claude Fable 5 · Claude Opus 4.7 · Claude Sonnet 4.6 · Claude Opus 4.6 · Claude Opus 4.5 · Claude Sonnet 4.5 · Claude Opus 4.1 · Claude Sonnet 4