Claude Sonnet 4.5

Anthropic · Released 29 Sep 2025 · claude-sonnet-4-5-20250929

ProprietaryRetires 30 Nov 2026CodingAgents

$3.00

Input price / 1M tokens

#47 of 61, cheapest first

$15.00

Output price / 1M tokens

#46 of 61, cheapest first

200K

Context window

#62 of 71

–

Output tokens / second

77.2%

SWE-bench Verified

#5 of 12

Summary

Claude Sonnet 4.5 is a proprietary model from Anthropic, released on 29 Sep 2025.

At $3.00 input and $15.00 output per million tokens, it is #47 of 61 on input price, cheapest first.

Its 200K-token context window ranks #62 of 71.

Deprecated Sonnet model; at launch Anthropic called it the best coding model in the world and the strongest model for building complex agents.

Benchmark	Score	Bar	Rank	Source
SWE-bench Verifiedaveraged over 10 trials, no test-time compute, 200K thinking budget	77.2%		#5 of 12	Anthropic Sonnet 4.5 launch postSelf-reported
OSWorldvariant written as 'OSWorld' in post text	61.4%		–	Anthropic Sonnet 4.5 launch postSelf-reported

Self-reported means the lab ran the test itself. A rank appears only where several labs report the same version of a benchmark.

Models with the most benchmarks in common with Claude Sonnet 4.5, and the closest scores.

#5 of 12

Real GitHub issues, fixed and tested

Compare Claude Sonnet 4.5 side by side

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Sources

price, cache prices, batch: platform.claude.com/docs/en/about-claude/pricing, checked 2 Oct 2026
context, max output, release, api id and alias, knowledge cutoff, modalities, deprecation: platform.claude.com/docs/en/models/sonnet-4-5/overview, checked 2 Oct 2026
deprecation date, retirement date, replacement: platform.claude.com/docs/en/about-claude/model-deprecations, checked 2 Oct 2026
200K context (no 1M): platform.claude.com/docs/en/build-with-claude/context-windows, checked 2 Oct 2026
minimum cacheable prompt length: platform.claude.com/docs/en/build-with-claude/prompt-caching, checked 2 Oct 2026
benchmarks, positioning: anthropic.com/news/claude-sonnet-4-5, checked 2 Oct 2026

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