Claude Sonnet 4.5
Snapshot claude-sonnet-4-5-20250929 (alias claude-sonnet-4-5). Extended thinking only. Training data cutoff Jul 2025. Retirement 'not sooner than 2026-09-29' - may be deprecated soon; check the deprecations page.
- Context window
- 200,000 tokens
- Max output
- 64,000 tokens
- Knowledge cutoff
- 2025-01
- Input
- text, image, pdf
- Output
- text
- License
- proprietary
- Pricing
- input: $3 · output: $15 · cache read: $0.3 (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-sonnet-4-5-20250929 | https://api.anthropic.com/v1/messages | docs |
| AWS Bedrock (InvokeModel) | anthropic.claude-sonnet-4-5-20250929-v1:0 | — | docs |
| Google Cloud Vertex AI | claude-sonnet-4-5@20250929 | — | docs |
| Microsoft Foundry (Azure) | claude-sonnet-4-5 | — | docs |
| Claude Platform on AWS | claude-sonnet-4-5 | — | docs |
| OpenRouter | anthropic/claude-sonnet-4.5 | openrouter.ai/anthropic/claude-sonnet-4.5 | — |
| Web app | — | claude.ai | — |
Notable capabilities (3)
- 30+ hour autonomous tasks: Anthropic reported it maintained focus for more than 30 hours on complex multi-step tasks. source
- SOTA SWE-bench Verified at launch: 77.2% on SWE-bench Verified; billed as 'the best coding model in the world' at release. source
- Computer use lead: 61.4% on OSWorld, up from 42.2% for Sonnet 4. source
Legacy Sonnet; migrate to claude-sonnet-5-5.
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-sonnet-4-5","max_tokens":16000,"messages":[{"role":"user","content":"Hello"}]}'
Sources:
- Model page: https://platform.claude.com/docs/en/models/sonnet-4-5/overview
- Announcement: https://www.anthropic.com/news/claude-sonnet-4-5
- 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 4.8 · Claude Opus 4.7 · Claude Sonnet 4.6 · Claude Opus 4.6 · Claude Opus 4.5 · Claude Opus 4.1 · Claude Sonnet 4