Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across system design, code security, and specification adherence. The model is designed for extended autonomous operation, maintaining task continuity across sessions and providing fact-based progress tracking.
Sonnet 4.5 also introduces stronger agentic capabilities, including improved tool orchestration, speculative parallel execution, and more efficient context and memory management. With enhanced context tracking and awareness of token usage across tool calls, it is particularly well-suited for multi-context and long-running workflows. Use cases span software engineering, cybersecurity, financial analysis, research agents, and other domains requiring sustained reasoning and tool use.
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).
| $3.00 | $15.00 | $0.30 | 0.90s | 41 tok/s | ||
| $3.00 | $15.00 | $0.30 | 0.92s | 35 tok/s | ||
| $3.00 | $15.00 | $0.30 | 1.54s | 33 tok/s | ||
| $3.00 | $15.00 | $0.30 | 0.62s | 30 tok/s | ||
| $3.00 | $15.00 | $0.30 | 5.29s | 32 tok/s | ||
Not used in Standard routing:Why these endpoints are not used | ||||||
| $3.30 | $16.50 | $0.33 | 1.32s | 44 tok/s | ||
| $3.30 | $16.50 | $0.33 | 0.92s | 47 tok/s | ||
- Input $3.00 / Output $15.0041 tok/s99.70% uptime
- Input $3.00 / Output $15.0035 tok/s98.98% uptime
- Input $3.00 / Output $15.0033 tok/s100.00% uptime
- Input $3.00 / Output $15.0030 tok/s98.92% uptime
- Input $3.00 / Output $15.0032 tok/s-- uptime
- Not used in Standard routing:Why these endpoints are not used
- Input $3.30 / Output $16.5044 tok/s100.00% uptime
- Input $3.30 / Output $16.5047 tok/s100.00% 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 4.5 — Price history
| $1.42 | $15.00 | 61.2% | 9.3% | ||
| $1.66 | $15.00 | 54.9% | 0.6% | ||
| $1.85 | $15.00 | 44.2% | 62.8% | ||
| $2.08 | $15.00 | 35.0% | 27.1% | ||
| $2.82 | $15.00 | 7.7% | 0.0% | ||
Not used in Standard routing:Why these endpoints are not used | |||||
| $3.18 | $16.44 | 11.3% | 0.0% | ||
| $3.30 | $16.50 | 0.0% | 0.0% | ||
- Effective in $1.42 / Effective out $15.00Token share9.3%
- Effective in $1.66 / Effective out $15.00Token share0.6%
- Effective in $1.85 / Effective out $15.00Token share62.8%
- Effective in $2.08 / Effective out $15.00Token share27.1%
- Effective in $2.82 / Effective out $15.00Token share0.0%
- Not used in Standard routing:Why these endpoints are not used
- Effective in $3.18 / Effective out $16.44Token share0.0%
- Effective in $3.30 / Effective out $16.50Token share0.0%
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).
P50, best across providers
P50, best provider
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.
Availability over the last 3 days
Last 72 hoursAvailability over the last 24 hours
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 4.5 Sonnet (Non-reasoning) GPQA Diamond | 72.7% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) HLE | 7.2% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) IFBench | 42.7% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) τ²-Bench Telecom | 70.5% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) AA-LCR | 54.0% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) CritPt | 0.0% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) LiveCodeBench | 59.0% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) Terminal-Bench Hard | 28.8% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) MMLU-Pro | 86.0% |
| Artificial Analysis | Claude 4.5 Sonnet (Non-reasoning) AIME 2025 | 37.0% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) Coding Index | 52.1 |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) Agentic Index | 15.8 |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) GPQA Diamond | 83.4% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) HLE | 17.8% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) IFBench | 57.3% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) τ²-Bench Telecom | 78.1% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) AA-LCR | 72.3% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) τ-Bench Banking | 24.5% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) GDPval-AA | 20.8% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) CritPt | 1.1% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) LiveCodeBench | 71.4% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) SciCode | 45.7% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) Terminal-Bench Hard | 35.6% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) Terminal-Bench 4.0 | 0.0% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) Terminal-Bench 2.1 | 55.8% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) MMLU-Pro | 87.5% |
| Artificial Analysis | Claude 4.5 Sonnet (Reasoning) AIME 2025 | 88.0% |
| Design Arena | Claude Sonnet 4.5 Models Arena 3D Elo | 1137 |
| Design Arena | Claude Sonnet 4.5 Models Arena Asciiart Elo | 1170 |
| Design Arena | Claude Sonnet 4.5 Models Arena Code Categories Elo | 1172 |
| Design Arena | Claude Sonnet 4.5 Models Arena Data Visualization Elo | 1164 |
| Design Arena | Claude Sonnet 4.5 Models Arena Game Development Elo | 1155 |
| Design Arena | Claude Sonnet 4.5 Models Arena SVG Elo | 1097 |
| Design Arena | Claude Sonnet 4.5 Models Arena UI Component Elo | 1151 |
| Design Arena | Claude Sonnet 4.5 Models Arena Website Elo | 1181 |
| Design Arena | Claude Sonnet 4.5 Agents Arena Full Stack Elo | 1025 |
| Design Arena | Claude Sonnet 4.5 Agents Arena Mobile Apps Elo | 1131 |
| Design Arena | Claude Sonnet 4.5 Agents Arena Webapps Elo | 1037 |
| Vals AI | Claude Sonnet 4.5 (Nonthinking) CorpFin v2 | 60.8% |
| Vals AI | Claude Sonnet 4.5 (Nonthinking) Finance Agent v1 | 49.2% |
| Vals AI | Claude Sonnet 4.5 (Nonthinking) MedCode | 40.6% |
| Vals AI | Claude Sonnet 4.5 (Nonthinking) MedScribe | 84.5% |
| Vals AI | Claude Sonnet 4.5 (Nonthinking) SAGE v1 | 32.9% |
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.
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.
Available through EU in-region routing
Anthropic: Claude Sonnet 4.5 is available through EU in-region routing. Requests sent to eu.openrouter.ai are decrypted in the EU and routed only to shared provider endpoints in Europe (the EU/EEA, the UK, and Switzerland).
- Providers in Europe
- Amazon Bedrock
- Prices in Europe
- Amazon Bedrock: $3.30/M tokens input, $16.50/M tokens output
- Base URL
https://eu.openrouter.ai/api/v1- Plan
- Requires Business or Enterprise. Self-serve on Business: no contract, no monthly minimum. OpenRouter Business for EU in-region routing
Fails closed: if no shared provider endpoint in Europe is available, the request errors instead of leaving the region. Requests served by your own BYOK key go to your deployment’s region, which you control. In-region routing docs
Frequently asked questions
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across system design, code security, and specification adherence.
Claude Sonnet 4.5 costs $3.00/M input tokens and $15.00/M output tokens, with separate rates for Cache Read at $0.30/M tokens, Cache Write at $3.75/M tokens, Cache Write (1h) at $6.00/M tokens, and Web Search at $10.00/1K calls.
Claude Sonnet 4.5 has a 1,000,000 token context window. It supports up to 64,000 completion tokens.
Yes. Claude Sonnet 4.5 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
Claude Sonnet 4.5 accepts text, images, and files such as PDFs as input and returns text.
Claude Sonnet 4.5 is served by 5 providers on OpenRouter: Claude Platform on AWS, Azure, Amazon Bedrock, Anthropic, and Google Vertex. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.
Claude Sonnet 4.5 was released on September 29, 2025. Its knowledge cutoff is January 31, 2025.