Anthropic
Claude Sonnet 5.5
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.
At a glance
- Input / 1M
- $2
- Output / 1M
- $10
- Context
- 1M
- Max output
- 128K
- Intelligence
- 56
- Released
- Sep 2026
Pricing
Claude Sonnet 5.5 API pricing
Per-token rates, plus what common tasks actually cost.
| Input tokensPer 1M tokens | $2 |
|---|---|
| Output tokensPer 1M tokens | $10 |
| Cached input (read)Per 1M tokens | $0.10 |
| Cache writePer 1M tokens | $2.50 |
| Web searchPer request | $0.01 |
Chat message
2K in, 500 out
$9
per 1,000 requests
Coding task
30K in, 4K out
$100
per 1,000 requests
Long document summary
150K in, 2K out
$320
per 1,000 requests
Benchmarks
Claude Sonnet 5.5 benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
56
Coding index
Not available
Agentic index
Not available
Specs
Context window and capabilities
What it can read, what it can write, and which API features it supports.
- Context window
- 1M tokens
- Max output
- 128K tokens
- Input types
- File, Image, Text
- Output types
- Text
- Reasoning effort
- Max, Extra high, High, Medium, Low
- Release date
- September 28, 2026
- Tool calling
- Structured outputs
- JSON mode
- Reasoning
- Temperature
- Stop sequences
- Deterministic seed
- Verbosity control
Compare
Claude Sonnet 5.5 vs other models
See how Claude Sonnet 5.5 stacks up head to head on price, benchmarks, and features.
VSClaude Sonnet 5.5 vs Claude Opus 5.5
Anthropic vs Anthropic
See comparisonVSClaude Sonnet 5.5 vs Claude Fable 5.1
Anthropic vs Anthropic
See comparisonVS
Claude Sonnet 5.5 vs GPT-6 Astra
Anthropic vs OpenAI
See comparisonVSClaude Sonnet 5.5 vs GPT-6.1 Sol
Anthropic vs OpenAI
See comparisonVSClaude Sonnet 5.5 vs Claude Opus 5
Anthropic vs Anthropic
See comparisonVSClaude Sonnet 5.5 vs Claude Fable 5
Anthropic vs Anthropic
See comparisonMore Claude Sonnet 5.5 comparisons
- Claude Sonnet 5.5 vs Muse Spark 1.3
- Claude Sonnet 5.5 vs GPT-6 Sol
- Claude Sonnet 5.5 vs GPT-5.6 Sol
- Claude Sonnet 5.5 vs Grok 4.7
- Claude Sonnet 5.5 vs GLM 5.3
- Claude Sonnet 5.5 vs DeepSeek V4.1 Flash
- Claude Sonnet 5.5 vs GLM 5.3 Flash
- Claude Sonnet 5.5 vs MiMo-V2.6-Flash
- Claude Sonnet 5.5 vs Hy4 preview
- Claude Sonnet 5.5 vs GPT-6 Luna
- Claude Sonnet 5.5 vs DeepSeek V4 Flash 0731
Alternatives
Claude Sonnet 5.5 alternatives
Similar models worth considering, and where each one has the edge.
Anthropic
Claude Opus 5.5
OpenAI
GPT-6 Astra
OpenAI
GPT-6.1 Sol
Want to learn about other models? Browse all models
FAQ
Frequently asked questions
How much does Claude Sonnet 5.5 cost?
Claude Sonnet 5.5 costs $2 per 1M input tokens and $10 per 1M output tokens through the API. A typical chat message costs about $9 per 1,000 messages.
What is the context window of Claude Sonnet 5.5?
Claude Sonnet 5.5 accepts up to 1M tokens of input and can write up to 128K tokens in a single response.
What is the best alternative to Claude Sonnet 5.5?
Claude Opus 5.5 from Anthropic is a strong alternative. It offers: higher intelligence score.
Can I use Claude Sonnet 5.5 alongside other models?
Yes. Shortcut Chat sends one prompt to Claude Sonnet 5.5 and any other models you pick at the same time, so you can compare answers side by side.
Try Claude Sonnet 5.5 next to every other model.
Use Claude Sonnet 5.5 alongside all the other models. Use one at a time, or multiple together. Get the best answer from every AI.