Claude Sonnet 5

Anthropic🇺🇸 United States
active
Context window1000K tokens
Input / 1M tokens$2
Output / 1M tokens$10

Version History

5.0major

Introduces 1M token context, 128K max output, removes sampling parameters (temperature, top_p, top_k), and implements new tokenizer generating ~30% more tokens than Sonnet 4.6 for English text.

5major

Claude Sonnet 5 is Anthropic's first Sonnet model of their latest generation, delivering near-Opus intelligence at Sonnet pricing. Key improvements include stronger multi-step reasoning, improved code navigation, and enhanced agentic reliability for production workflows.

Benchmark Scores

Full leaderboard →
91.1%
GPQA
39.4%
Hallucination Rate
74.0 tokens_per_sec
Speed (tok/s)
72.7%
SWE-bench Verified

Coverage

model releaseAnthropic

Claude Sonnet 5 ships with 1M token context and new tokenizer that increases costs 30-40% for English text

Anthropic released Claude Sonnet 5 with a 1 million token context window and 128,000 token maximum output. The model removes traditional sampling parameters and introduces a new tokenizer that generates approximately 30% more tokens than Sonnet 4.6 for the same English text—effectively a significant price increase despite unchanged nominal rates of $3/million input and $15/million output tokens.

2 min read