Has Anthropic released Claude Opus 5.5?
Yes. Anthropic released it on September 22, 2026, with Claude API ID claude-opus-5-5.
CL
Claude Opus 5.5
Also known as: Opus 5.5
Release date: 2026-09-22Updated: 2026-09-23Knowledge cutoff: 2026-06Available at least until: 2027-09-22Views: 103
Parameters
No data
Context length
1M
Multilingual
No data
Reasoning ability
No data
Anthropic released Claude Opus 5.5 on September 22, 2026. It offers a 1M-token context window, 128K maximum output, text and image input, and always-on adaptive thinking. Claude API standard pricing is $4 per million input tokens and $20 per million output tokens.
Data sourced primarily from official releases (GitHub, Hugging Face, papers), then benchmark leaderboards, then third-party evaluators. Learn about our data methodology
Claude Opus 5.5
Model basics
Reasoning traces
Supported
Thinking modes
Thinking Level · Adaptive Thinking (Default)
Context length
1M tokens
Max output length
128K tokens
Model type
Reasoning model
Modality (in / out)
Text, Image → Text
Release date
2026-09-22
Model file size
No data
MoE architecture
No
Total params / Active params
No data / Not applicable
Knowledge cutoff
2026-06
Claude Opus 5.5
Open source & experience
Claude Opus 5.5
Official resources
DataLearnerAI blog
N/A
Claude Opus 5.5
API details
API speed
No data
💡Default unit: $/1M tokens. If vendors use other units, follow their published pricing.
Standard
| Type | Condition | Input | Output |
|---|---|---|---|
| Text | - | $4.00/ 1M tokens | $20.00/ 1M tokens |
Batch
| Type | Condition | Input | Output |
|---|---|---|---|
| Text | - | $2.00/ 1M tokens | $10.00/ 1M tokens |
Faster
| Type | Condition | Input | Output |
|---|---|---|---|
| Text | - | $8.00/ 1M tokens | $40.00/ 1M tokens |
Cache PricingPrompt Cache
| Type | TTL | Write | Read |
|---|---|---|---|
| Text | 5m | $5.00/ 1M tokens | $0.200/ 1M tokens |
| Text | 1h | $8.00/ 1M tokens | — |
“—” means the modality is not billed in that direction, or the vendor has not published a price for it.
Claude Opus 5.5
Benchmark Results
Claude Opus 5.5 currently shows benchmark results led by HLE (1 / 566, score 67.70), Terminal-Bench 4.0 (1 / 92, score 66.40), CursorBench 4.0 (1 / 46, score 57.80). This page also consolidates core specs, context limits, and API pricing so you can evaluate the model from benchmark results and deployment constraints together.
AI Agent - Tool Usage
3 evaluationsBenchmark / mode
Score
Rank/total
Coding and Software Engineer
4 evaluationsBenchmark / mode
Score
Rank/total
Claude Opus 5.5
Publisher
Anthropic
View publisher details Claude Opus 5.5
Model Overview
Official release
Claude Opus 5.5 was released by Anthropic on September 22, 2026. Its Claude API model ID is claude-opus-5-5. Anthropic positions it for long-running agentic coding and knowledge work; it is available through the Claude API and major cloud platforms.
Specifications
Anthropic documents a 1 million-token context window, 128,000-token maximum output, text and image inputs, and text output. Adaptive thinking is always on; the default effort is medium. Reliable knowledge and training-data cutoffs are June 2026. Parameter count and model architecture have not been disclosed. Anthropic says the model will not be retired before September 22, 2027; that is a minimum support date, not a scheduled retirement.
API pricing
Standard Claude API prices per million tokens are $4 input and $20 output. Cache reads cost $0.20, five-minute cache writes $5, and one-hour cache writes $8. Batch API input and output receive a 50% discount. Fast mode costs $8 input and $40 output per million tokens.
Published evaluations
Anthropic reports 66.4% on Terminal-Bench 4.0 at xhigh effort, 58.7% on Terminal-Bench-Science 0.1, 67.7% on Humanity's Last Exam with tools, and 40.0% on AutomationBench. These are vendor-reported results with differing tools, effort settings and safeguards; they should not be read as identical test conditions across providers.
Official sources
Claude Opus 5.5
FAQ
What are its context and output limits?
The standard model supports up to 1 million input-context tokens and 128,000 output tokens.
How much does Claude Opus 5.5 cost?
Standard Claude API pricing is $4 per million input tokens and $20 per million output tokens. Cache reads cost $0.20 per million tokens; batch input and output receive a 50% discount.
Can adaptive thinking be disabled?
No. Adaptive thinking is always on. The effort parameter controls its depth and defaults to medium.
DataLearner on WeChat
Follow DataLearner on WeChat for AI model updates and research notes.
