Model · Multimodal language model
Claude Sonnet 4.5
A dated, pinned multimodal Claude release in legacy status, available through Anthropic's developer API and documented third-party cloud platforms, without downloadable model weights.
- Developer
- Anthropic
- Distribution
- Developer API · Third-party hosting
- Artifact licensing
- Proprietary access
- License scope
- Reviewed release artifacts and mandatory terms; not an assessment of training code or training data openness.
- Licenses
- Anthropic Commercial Terms of Service
- Boundary
- This record represents the fixed Claude Sonnet 4.5 snapshot identified by claude-sonnet-4-5-20250929, which the claude-sonnet-4-5 alias resolves to. Anthropic's API, Amazon Bedrock, Google Cloud, Microsoft Foundry, Claude Platform on AWS, Claude applications, and later Sonnet releases remain separate service or product boundaries.
Risk statements
“ASL-3” · Safeguard standard
Claude Sonnet 4.5 is being released under our AI Safety Level 3 (ASL-3) protections, as per our framework that matches model capabilities with appropriate safeguards. These safeguards include filters called classifiers that aim to detect potentially dangerous inputs and outputs—in particular those related to chemical, biological, radiological, and nuclear (CBRN) weapons.
- Risk areas
- Biological or chemical
- Covers
- The model itself
Read the developer's statement ↗ · 2026-10-07 · Research confidence: High
Anthropic states that this release ships under the “ASL-3” safeguard standard for biological or chemical capability. The statement covers the model itself. This is the developer's own statement, not an Atlas risk rating.
Open in the directory → Open official model page ↗
Editorial ratings appear in the directory beside the profile they belong to and are never compared across collections.