anthropic/claude-sonnet-4.5Claude Sonnet 4.5 is Anthropic’s proprietary AI model, released Sep 29, 2025. It costs $3/M input and $15/M output tokens, and handles a 1M-token context window.
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows.
Scores on standardized evaluations. Higher is better — and rank shows where Claude Sonnet 4.5 lands among all models tracked on Model Beat.
Abstract visual reasoning
Harder abstract reasoning
Graduate-level scientific reasoning
Frontier of human expert knowledge
Common-sense trick questions
Factual accuracy & hallucination
Novel ML problem-solving
Code performance optimization
Real GitHub issue resolution
Human-rated web development
Olympiad-qualifier math
Research-level math problems
Hardest research math
Hardest competition math
Economically valuable work
Autonomous task length
Command-line agentic tasks
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows.
Claude Sonnet 4.5 is an AI model developed by Anthropic, part of the Claude family, released Sep 29, 2025.
Claude Sonnet 4.5's list price from Anthropic is $3 per million input tokens and $15 per million output tokens.
Claude Sonnet 4.5 supports a context window of up to 1M tokens.
On standardized evaluations tracked by Epoch AI, Claude Sonnet 4.5 scores 97.7% on MATH Level 5, 46.5% on Terminal-Bench, 50.3% on GDPval (win/tie rate).
Claude Sonnet 4.5 is a proprietary model (API access), available through its provider's API rather than as a downloadable open-weight model.
Benchmark data from Epoch AI (CC BY) and Artificial Analysis; pricing, specs & descriptions from OpenRouter. Data updated Jul 30, 2026.