Claude Sonnet 4.5
by Anthropic
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 benchm
Models
Claude Sonnet 4.5
Added 10 July 2026
Overview
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...
Best for
Best for
Daily driver for agentic coding and analysis
Use cases
- Claude Code / Cursor agent loops
- research synthesis
- customer support agents
How to use / API access
Call via OpenRouter with model id `anthropic/claude-sonnet-4.5`.
- openrouter ·
anthropic/claude-sonnet-4.5Docs
OpenRouter id: anthropic/claude-sonnet-4.5
Benchmarks
- Intelligence Index (artificial-analysis): 20.7 index
- Coding Index (artificial-analysis): 52.1 index
- Agentic Index (artificial-analysis): 15.8 index
- Design Arena 3d (other): 1158 elo · #65
- Design Arena asciiart (other): 1207 elo · #22
- Design Arena codecategories (other): 1184 elo · #62
- Design Arena dataviz (other): 1167 elo · #71
Enterprise DNA angle
Omni wires Sonnet into scheduled jobs and CRM write-backs so model quality becomes an operating layer, not a chat tab.
Notes
Claude Sonnet 4.5 is listed in the EDNA Models directory from the OpenRouter catalogue.
Pros
- Latest Sonnet-class balance of speed and quality
- Excellent for tool-using agents
- Large context for multi-file refactors
Cons
- Premium pricing vs open weights
- Closed model — vendor lock-in on Anthropic/OpenRouter path
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