Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade. It is especially strong at building features, fixing bugs, and producing polished documents, slides, and spreadsheets, and it writes and communicates more clearly than its predecessor.
Thinking is always on, so effort is the main lever for trading off depth, latency, and cost, and lower effort settings keep it responsive for everyday agentic loops.
Providers
Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).
| $1.00 | $5.00 | $0.05 | -- | -- |
Input $1.00 / Output $5.00-- tok/s-- uptime
Pricing
The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.
Weighted average
Claude Sonnet 5.5 (batch) — Price history
| $0.00 | $0.00 | 13.2% | 100.0% |
- Effective in $0.00 / Effective out $0.00Token share100.0%
Performance
Throughput is how fast the model writes (tokens per second — higher is better). Latency is total round-trip time (lower is better). TTFT is time-to-first-token — how long before you see anything appear (lower is better).
Uptime
Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.
Not enough uptime data to display yet.
When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.
Benchmarks
Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.
| Source | Benchmark | Score |
|---|---|---|
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) Intelligence Index | 25.6 |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) HLE | 36.2% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) AA-LCR | 76.0% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) GDPval-AA | 34.1% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) CritPt | 11.4% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) SciCode | 49.1% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) Terminal-Bench 4.0 | 20.7% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) AA-Omniscience Accuracy | 46.0% |
| Artificial Analysis | Claude Sonnet 5.5 (Low, Default Fallback) AA-Omniscience Non-Hallucination Rate | 52.3% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) Intelligence Index | 41.5 |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) HLE | 45.8% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) AA-LCR | 78.0% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) GDPval-AA | 52.6% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) CritPt | 24.6% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) SciCode | 53.7% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) Terminal-Bench 4.0 | 43.9% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) AA-Omniscience Accuracy | 50.3% |
| Artificial Analysis | Claude Sonnet 5.5 (High, Default Fallback) AA-Omniscience Non-Hallucination Rate | 36.4% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) Intelligence Index | 30.8 |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) HLE | 39.8% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) AA-LCR | 76.3% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) GDPval-AA | 41.3% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) CritPt | 16.9% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) SciCode | 52.9% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) Terminal-Bench 4.0 | 29.8% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) AA-Omniscience Accuracy | 45.8% |
| Artificial Analysis | Claude Sonnet 5.5 (Medium, Default Fallback) AA-Omniscience Non-Hallucination Rate | 50.0% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) Intelligence Index | 54.5 |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) HLE | 55.0% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) AA-LCR | 82.7% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) GDPval-AA | 66.9% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) CritPt | 31.4% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) SciCode | 61.0% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) Terminal-Bench 4.0 | 63.6% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) AA-Omniscience Accuracy | 51.5% |
| Artificial Analysis | Claude Sonnet 5.5 (Max, Default Fallback) AA-Omniscience Non-Hallucination Rate | 56.7% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) Intelligence Index | 49.9 |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) HLE | 50.0% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) AA-LCR | 79.7% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) GDPval-AA | 62.1% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) CritPt | 31.1% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) SciCode | 57.3% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) Terminal-Bench 4.0 | 57.1% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) AA-Omniscience Accuracy | 50.9% |
| Artificial Analysis | Claude Sonnet 5.5 (Xhigh, Default Fallback) AA-Omniscience Non-Hallucination Rate | 38.3% |
| Design Arena | Claude Sonnet 5.5 Agents Arena Androidnative Elo | 1251 |
| Design Arena | Claude Sonnet 5.5 Agents Arena Blender3d Elo | 1266 |
| Design Arena | Claude Sonnet 5.5 Agents Arena Codetovideo Elo | 1310 |
| Design Arena | Claude Sonnet 5.5 Agents Arena Mobile Apps Elo | 1260 |
| Design Arena | Claude Sonnet 5.5 Agents Arena Pdf Elo | 1244 |
| Design Arena | Claude Sonnet 5.5 Agents Arena Spreadsheet Elo | 1238 |
| Design Arena | Claude Sonnet 5.5 Agents Arena Webapps Elo | 1296 |
| Design Arena | Claude Sonnet 5.5 Models Arena 3D Elo | 1401 |
| Design Arena | Claude Sonnet 5.5 Models Arena Code Categories Elo | 1344 |
| Design Arena | Claude Sonnet 5.5 Models Arena Data Visualization Elo | 1359 |
| Design Arena | Claude Sonnet 5.5 Models Arena Game Development Elo | 1386 |
| Design Arena | Claude Sonnet 5.5 Models Arena SVG Elo | 1299 |
| Design Arena | Claude Sonnet 5.5 Models Arena UI Component Elo | 1387 |
| Design Arena | Claude Sonnet 5.5 Models Arena Website Elo | 1309 |
| Vals AI | Claude Sonnet 5.5 Access to Justice Benchmark | 74.9% |
| Vals AI | Claude Sonnet 5.5 BioMysteryBench | 81.1% |
| Vals AI | Claude Sonnet 5.5 ClaimBench | 100.0% |
| Vals AI | Claude Sonnet 5.5 Code Migration v1.1 | 86.9% |
| Vals AI | Claude Sonnet 5.5 CyberBench v1.1 | 59.6% |
| Vals AI | Claude Sonnet 5.5 EMB v1.1 | 75.9% |
| Vals AI | Claude Sonnet 5.5 Finance Agent v2.1 | 67.3% |
| Vals AI | Claude Sonnet 5.5 Vals Finance Index | 64.5% |
| Vals AI | Claude Sonnet 5.5 Financial Coaching Bench | 74.9% |
| Vals AI | Claude Sonnet 5.5 HLAB-Vals-1.1 | 10.4% |
| Vals AI | Claude Sonnet 5.5 Immigration | 69.0% |
| Vals AI | Claude Sonnet 5.5 IOI | 83.1% |
| Vals AI | Claude Sonnet 5.5 Vals Legal Index | 68.0% |
| Vals AI | Claude Sonnet 5.5 Legal Research Bench | 48.1% |
| Vals AI | Claude Sonnet 5.5 MedCode | 52.9% |
| Vals AI | Claude Sonnet 5.5 MedScribe | 91.1% |
| Vals AI | Claude Sonnet 5.5 MysteryMechanism | 49.1% |
| Vals AI | Claude Sonnet 5.5 ProgramBench | 6.5% |
| Vals AI | Claude Sonnet 5.5 ProofBench v1.1 | 100.0% |
| Vals AI | Claude Sonnet 5.5 Public Benefits Bench v1.1 | 67.2% |
| Vals AI | Claude Sonnet 5.5 SAGE | 88.0% |
| Vals AI | Claude Sonnet 5.5 Vals Science Index | 59.1% |
| Vals AI | Claude Sonnet 5.5 SRE Bench | 30.2% |
| Vals AI | Claude Sonnet 5.5 SWE-bench Multimodal | 58.3% |
| Vals AI | Claude Sonnet 5.5 Tax Agent Bench | 42.0% |
| Vals AI | Claude Sonnet 5.5 Terminal-Bench 4.0 | 64.1% |
| Vals AI | Claude Sonnet 5.5 Terminal-Bench-Science | 47.1% |
| Vals AI | Claude Sonnet 5.5 Vals Index | 70.9% |
| Vals AI | Claude Sonnet 5.5 Vibe Code Bench v1.1 | 92.4% |
Apps
Public apps that send the most traffic to this model. Good signal for what real production workloads look like — and a hint at which use cases this model is best suited for.
Not enough data for apps using this model yet.
Activity
Token volume and request traffic to this model over time.
API
Drop-in code to call this model. OpenRouter's API is OpenAI-compatible — most SDKs work by just swapping the base URL. The only thing that changes between models is the model slug below.
Anthropic: Claude Sonnet versions
Not currently available through EU in-region routing. In-region routing docs
Documentation
Guides, cookbooks, blog posts, and tools for building with Anthropic: Claude Sonnet 5.5 (batch) on OpenRouter.
- Claude 5.5 Migration GuideCookbook
- Reranking in RAG: How to Fix Bad Retrieval with a RerankerBlog post
- How to Benchmark LLMsBlog post
- MCP vs CLI vs Skills: What Each Costs in ContextBlog post
- Build an AI Code Reviewer with OpenRouterBlog post
- Claude Opus vs Sonnet vs Haiku: Which Should You Use?Blog post
- How Much Does Claude Code Cost? Real Session Costs by ModelBlog post
- Hit Your Claude Code Usage Limit? How to Keep CodingBlog post
- Claude 529 Overloaded: What It Means and How to Fix ItBlog post
Frequently asked questions
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade. It is especially strong at building features, fixing bugs, and producing polished documents, slides, and spreadsheets, and it writes and communicates more clearly than its predecessor.
The Claude Sonnet 5.5 (batch) documentation on OpenRouter includes the Claude 5.5 Migration Guide cookbook, the Reranking in RAG: How to Fix Bad Retrieval with a Reranker blog post, the How to Benchmark LLMs blog post, the MCP vs CLI vs Skills: What Each Costs in Context blog post, the Build an AI Code Reviewer with OpenRouter blog post, the Claude Opus vs Sonnet vs Haiku: Which Should You Use? blog post, the How Much Does Claude Code Cost? Real Session Costs by Model blog post, the Hit Your Claude Code Usage Limit? How to Keep Coding blog post, and the Claude 529 Overloaded: What It Means and How to Fix It blog post. The quickstart covers API keys and your first request, and the API reference lists every parameter.
Claude Sonnet 5.5 (batch) costs $1.00/M input tokens and $5.00/M output tokens, with separate rates for Cache Read at $0.05/M tokens, Cache Write at $1.25/M tokens, Cache Write (1h) at $2.00/M tokens, and Web Search at $10.00/1K calls.
Claude Sonnet 5.5 (batch) has a 1,000,000 token context window. It supports up to 128,000 completion tokens.
Yes. Claude Sonnet 5.5 (batch) accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
Claude Sonnet 5.5 (batch) accepts text, images, and files such as PDFs as input and returns text.
Claude Sonnet 5.5 (batch) is served by 1 provider on OpenRouter: Anthropic.
Claude Fable 5.2, Claude Haiku 5.5, Claude Opus 5.5 and 12 more are other text models from Anthropic.
Claude Sonnet 5.5 (batch) was released on September 28, 2026.