Anthropic: Claude Sonnet 4.5
Analysis Summary
Claude Sonnet 4.5 is Anthropic's mid-cycle Sonnet release, with an intelligence index of 29.3 and an agentic index of 49.6. MMLU Pro at 0.860 and GPQA at 0.727 reflect strong general knowledge, and TerminalBench Hard at 0.288 shows reliable tool execution. Vision, function calling, and a 1 million token context window make it one of the most capable all-round models at this tier.
For businesses, Sonnet 4.5 is well suited to client-facing content workflows, long-document analysis, agentic task automation, and multimodal pipelines. The 1M context is a meaningful advantage for codebase review or large report analysis. Its math index of 37 is lower than peers, so quantitative reasoning tasks should be validated carefully.
Pricing at $3 input / $15 output is premium for this intelligence tier, but Anthropic's reliability, instruction-following quality, and enterprise support justify the cost for teams where output quality and consistency are critical. This is a strong default choice for businesses already in the Anthropic ecosystem.
Assessed June 30, 2026
Editorial notes
Claude Sonnet 4.5 from Anthropic combines a 1M token context, vision, tool use, and strong instruction following with an agentic index of 49.6, suited to client-facing and agentic business workflows.
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
Performance Profile
How Anthropic: Claude Sonnet 4.5 compares
Anthropic: Claude Sonnet 4.5 ranks #86 of 385 AI models we track for overall intelligence, #92 of 293 for agentic tasks. Its 1M-token context window is larger than 91% of the models we list. At $3.00 per million input tokens it is cheaper than 10% of comparable models.
About Anthropic: Claude Sonnet 4.5
Claude Sonnet 4.5 is Anthropicās 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..
Capabilities
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Content
Benchmark data from Artificial Analysis and Hugging Face
How does Anthropic: Claude Sonnet 4.5 stack up?
Compare side-by-side with other professional models.
Model Information
| OpenRouter ID |
anthropic/claude-sonnet-4.5
|
| Provider | anthropic |
| Release Date | September 29, 2025 |
| Context Length | 1,000,000 tokens |
| Max Completion | 64,000 tokens |
| Status | Active |
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $3.00 | $0.003000 |
| Output | $15.00 | $0.015000 |
Live Performance
Live endpoint metrics, refreshed every 30 minutes.
Leaderboard Categories
External Resources
Frequently asked questions about Anthropic: Claude Sonnet 4.5
How much does Anthropic: Claude Sonnet 4.5 cost?
Anthropic: Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens.
What is the context window of Anthropic: Claude Sonnet 4.5?
Anthropic: Claude Sonnet 4.5 has a context window of 1,000,000 tokens (1M).
What can Anthropic: Claude Sonnet 4.5 do?
Anthropic: Claude Sonnet 4.5 supports image/vision input, tool use, and function calling.
Who created Anthropic: Claude Sonnet 4.5?
Anthropic: Claude Sonnet 4.5 is developed by Anthropic and was released on September 29, 2025.
