Claude Opus 5.5
AvailableClaude Opus 5.5 is Anthropic's frontier model released 2026-09-22, succeeding Claude Opus 5. It targets long-running agentic coding and knowledge work, delivering roughly Claude Fable 5.1-level quality on most tasks at about 40% lower running cost than Opus 5 for a typical token-billed workload. Text and image input, text output; 1,000,000-token context window and 128,000 max output tokens (up to 300k output via the Batch API with a beta header). Reliable knowledge cutoff June 2026 (up from May 2026 on Opus 5). API list pricing: $4 / 1M input, $20 / 1M output, $0.20 / 1M cache reads — a 20% cut to input/output token prices and a 60% cut to cached-read price versus Opus 5.
Specifications
- License
- Proprietary · Proprietary
- Weights
- Not released
- Architecture
- unknown
- Parameters
- Undisclosed
- Context window
- 1M tokens
- Max output
- 128K tokens
- Knowledge cutoff
- Jun 1, 2026
- Price (in / out, $/M)
- $4 / $20
- Modalities
- TextVisionCode
Benchmarks
No benchmark scores recorded yet. Spotted some? Submit a correction.
Vendor-reported figures are claims until independently verified. See methodology.