When was Claude Sonnet 4 released?

Claude Sonnet 4 was released by Anthropic on Thursday, May 22 2025.

Who made Claude Sonnet 4?

Claude Sonnet 4 was built by Anthropic. AI safety company building the Claude family of models. Founded in 2021 by former OpenAI researchers.

What benchmark scores did Claude Sonnet 4 get?

Claude Sonnet 4 reports 3 tracked benchmark scores — BullshitBench v2: 30%; SWE-Bench Verified: 72.7%; GPQA Diamond: 75.4%. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data.

What is the context window of Claude Sonnet 4?

Claude Sonnet 4 has a context window of 200k. That is the maximum amount of input plus output the model can hold in a single request.

Is Claude Sonnet 4 open source?

No. Claude Sonnet 4 is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

What came before and after Claude Sonnet 4?

Anthropic's previous tracked release was Claude 3.7 Sonnet on Feb 24 2025, 87 days earlier. It was followed by Claude Opus 4 on May 22 2025.

Claude Sonnet 4

Released May 22 2025

Claude Sonnet 4 is an AI model released by Anthropic on Thursday, May 22 2025, 87 days after Claude 3.7 Sonnet. It has a 200k token context window. Benchmark results (shown below) cover BullshitBench v2, SWE-Bench Verified, and GPQA Diamond.

Benchmarks

Coding

SWE-Bench Verified

72.7%

#34 of 66

Reasoning & science

GPQA Diamond

75.4%

#45 of 66

Robustness

BullshitBench v2

30%

#60 of 97

Compare Claude Sonnet 4 with

Claude Sonnet 4

Suggested comparisons

Claude Sonnet 4vsClaude Haiku 5.5 Claude Sonnet 4vsGPT-6.1 Sol Claude Sonnet 4vsGemini 4 Argon Claude Sonnet 4vsMuse Spark Open Claude Sonnet 4vsGrok 4.7 Claude Sonnet 4vsDeepSeek-V4.1-Flash-1017 Claude Sonnet 4vsMistral Large 4 Claude Sonnet 4vsKimi K3 Claude Sonnet 4vsGLM-5.3-Flash Claude Sonnet 4vsQwen3.8-Max-0902 Claude Sonnet 4vsNemotron 3.5 Super VL

Frequently asked questions

: Claude Sonnet 4 was released by Anthropic on Thursday, May 22 2025.
: Claude Sonnet 4 was built by Anthropic. AI safety company building the Claude family of models. Founded in 2021 by former OpenAI researchers.
: Claude Sonnet 4 reports 3 tracked benchmark scores — BullshitBench v2: 30%; SWE-Bench Verified: 72.7%; GPQA Diamond: 75.4%. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data.
: Claude Sonnet 4 has a context window of 200k. That is the maximum amount of input plus output the model can hold in a single request.
: No. Claude Sonnet 4 is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.
: Anthropic's previous tracked release was Claude 3.7 Sonnet on Feb 24 2025, 87 days earlier. It was followed by Claude Opus 4 on May 22 2025.