By the toolist.ai editors. Researched from public sources, not hands-on tested by toolist.ai. Updated October 13, 2026; prices checked October 13, 2026.
Claude Sonnet 5.5: price, context window and benchmarks
Claude Sonnet 5.5 is Anthropic's current Sonnet model, which Anthropic calls its best combination of speed and intelligence, at $2 per million input tokens and $10 per million output tokens, the same as Claude Sonnet 5. Artificial Analysis puts it at 56.0 on its Intelligence Index at max effort and 46.8 at high, the API default.
Best for
- Well-scoped everyday tasks, bug fixing and polished documents, slides and spreadsheets, which Anthropic says are its strengths
- Replacing Claude Sonnet 5: Anthropic calls Sonnet 5.5 a clear upgrade, at the same input and output prices and half the cache-read price
- Prompt-heavy agents, since cache reads cost $0.10 per million tokens against $2 for fresh input
Key facts
| Fact | Claude Sonnet 5.5 | Source |
|---|---|---|
| Provider | Anthropic | Claude docs: Pricing |
| API model name | claude-sonnet-5-5 | Claude docs: Claude Sonnet 5.5 |
| Released | September 28, 2026 | Anthropic: Introducing Claude Sonnet 5.5 |
| Input price | $2 per million tokens | Claude docs: Pricing |
| Cached input price | $0.10 per million tokens | Claude docs: Pricing |
| Output price | $10 per million tokens | Claude docs: Pricing |
| Context window | 1,000,000 tokens | Claude docs: Claude Sonnet 5.5 |
| Maximum output | 128,000 tokens | Claude docs: Claude Sonnet 5.5 |
| Knowledge cutoff | June 2026 | Claude docs: Claude Sonnet 5.5 |
| Input and output | Text and images in; text out | Claude docs: Claude Sonnet 5.5 |
| Reasoning | Adaptive thinking is on by default; the between_tools setting turns off up-front thinking at high effort or below. Effort levels low to max; high is the API default | Claude docs: What's new in Claude Sonnet 5.5 |
| API and cloud platforms | Claude API, Amazon Bedrock, Claude Platform on AWS, Google Cloud and Microsoft Foundry | Claude docs: Claude Sonnet 5.5 |
| In the apps | Sonnet models are in the Claude apps on every plan, Free to Enterprise; the plan table names model families, not versions | Claude plans and pricing |
| Data retention | Available under zero data retention arrangements; it is not one of the models that require 30-day retention | Claude docs: API and data retention |
Cache writes cost $2.50 per million tokens (5-minute cache) or $4 (1-hour cache). The Batch API costs half. There is no long-context surcharge and no fast mode.
What Claude Sonnet 5.5 costs a month
Three typical workloads, priced at the standard API rates above. We calculated these; the provider does not publish them.
| Workload | Tokens a month | Cost a month |
|---|---|---|
| Support chatbot 100,000 replies, each 3,000 input and 400 output tokens, no caching | 300M in, 40M out | $1,000 |
| Document Q&A 5,000 questions over the same 60,000-token document set (90% cache hits), 800 output tokens each | 300M in, 4M out | $127 |
| Coding agent 200 tasks, each 1.5 million input tokens (90% cache hits) and 50,000 output tokens | 300M in, 10M out | $187 |
Reasoning models bill their thinking as output tokens, so heavy reasoning can raise the output count several times. Cache-write charges are not included.
Benchmarks
| Benchmark | Score | Source |
|---|---|---|
| Artificial Analysis Intelligence Index max effort | 56.0 | Artificial Analysis: Claude Sonnet 5.5 (max) |
| Intelligence Index at everyday effort high effort, the API default | 46.8 | Artificial Analysis: Claude Sonnet 5.5 (high) |
| Coding Agent Index Claude Code harness, max effort | 68.4 | Artificial Analysis: Coding agents |
| Terminal-Bench 4.0 max effort | 63.6% | Artificial Analysis: Claude Sonnet 5.5 (max) |
| Humanity's Last Exam max effort | 55.0% | Artificial Analysis: Claude Sonnet 5.5 (max) |
| GDPval-AA v2.1 (Elo) max effort | 1838 | Artificial Analysis: Claude Sonnet 5.5 (max) |
| SciCode max effort | 61.0% | Artificial Analysis: Claude Sonnet 5.5 (max) |
| Terminal-Bench-Science 0.1 max effort | 53.3% | Artificial Analysis: Claude Sonnet 5.5 (max) |
Speed: about 96.8 output tokens a second, 14.6 seconds to the first token (high effort, Anthropic API; Artificial Analysis: Claude Sonnet 5.5 (high)).
Benchmark and speed data marked as such come from Artificial Analysis.
What changed
Compared with Claude Sonnet 5, input and output prices stay the same and cache reads halve, from $0.20 to $0.10 per million tokens. Thinking can no longer be turned off with "disabled"; the new between_tools setting turns off up-front thinking instead. Forced tool use is no longer supported, effort levels are recalibrated, and the minimum cacheable prompt drops from 1,024 to 512 tokens. (Claude docs: What's new in Claude Sonnet 5.5)
Claude Sonnet 5.5 compared
- Claude Haiku 5.5 vs Claude Sonnet 5.5
- Claude Opus 5.5 vs Claude Sonnet 5.5
- GPT-6.1 Sol vs Claude Sonnet 5.5
Other models
- Gemini 4 Argon: $2 in, $10 out per million tokens
- Muse Wonder: $4 in, $20 out per million tokens
- Claude Haiku 5.5: $0.10 in, $0.50 out per million tokens
- GPT-6.1 Sol: $2 in, $10 out per million tokens
- Claude Opus 5.5: $4 in, $20 out per million tokens
- GPT-6 Sol: $2 in, $10 out per million tokens
- GPT-6 Astra: $10 in, $50 out per million tokens
- Claude Fable 5.1: $10 in, $50 out per million tokens
- Claude Opus 5: $5 in, $25 out per million tokens
All prices side by side: AI model API price table. How we research: our method.
Sources
- Anthropic: Introducing Claude Sonnet 5.5 (checked 2026-10-13)
- Claude docs: Claude Sonnet 5.5 (checked 2026-10-13)
- Claude docs: What's new in Claude Sonnet 5.5 (checked 2026-10-13)
- Claude docs: Pricing (checked 2026-10-13)
- Claude plans and pricing (checked 2026-10-13)
- Claude docs: API and data retention (checked 2026-10-13)
- Artificial Analysis: Claude Sonnet 5.5 (max) (checked 2026-10-13)
- Artificial Analysis: Claude Sonnet 5.5 (high) (checked 2026-10-13)
- Artificial Analysis: Coding agents (checked 2026-10-13)
- OpenRouter: Claude Sonnet 5.5 (checked 2026-10-13)