Claude Opus 5.5
Claude Opus 5.5 is the first released Claude 5.5 tier, designed for sustained agentic coding and professional work. Anthropic positions it near Fable 5.1 on most workloads with substantially lower cost than Opus 5, partly through token efficiency. It has always-on adaptive thinking, a million-token context, text and image input, and broad tool access. Effort settings control the latency and computation devoted to a task.
2026-09-22
Unreleased
Undisclosed proprietary architecture
Proprietary
Specifications
- Parameters
- Unreleased
- Architecture
- Undisclosed proprietary architecture
- License
- Proprietary
- Context Window
- 1,000,000 tokens
- Max Output
- 128,000 tokens
- Training Data Cutoff
- 2026-06
- Type
- multimodal
- Modalities
- textimage
Benchmark Scores
Advanced Specifications
- Model Family
- Claude
- API Access
- Available
- Chat Interface
- Available
- Multilingual Support
- Yes
- Variants
- claude-opus-5-5
Capabilities & Limitations
- Capabilities
- agentic codingadaptive thinkingvisioncomputer usetool use
- Known Limitations
- Can make factual or coding errors; tool results and important outputs require verification.Longer reasoning and agent work increase latency and token consumption.
- Notable Use Cases
- long-running engineeringprofessional analysisdocument workflows
- Function Calling Support
- Yes
- Tool Use Support
- Yes