We’ve released our evaluation of Claude Sonnet 4 (Thinking) across all of our benchmarks!

• Claude Sonnet 4 (Thinking) seriously underperforms when compared to its predecessor Claude 3.7 Sonnet (Thinking) on our proprietary TaxEval and ContractLaw benchmarks.
• Claude Sonnet 4 (Thinking) significantly outperformed Claude Sonnet 4 (Nonthinking) on our reasoning benchmarks. For example, Claude Sonnet 4 (Thinking) scored 76.3% and Claude Sonnet 4 (Nonthinking) scored 38.5% on our AIME benchmark.
• Claude Sonnet 4 (Thinking) is consistently in the top 10 across most of our benchmarks, though it is never the SOTA model.
• The model latency is high when reasoning is enabled with a high token budget. On AIME, the model responded in four minutes, on average, with some questions taking over ten minutes.

The full writeups are linked in the comments. The final determinant of the Claude 4 family strengths will come from Opus 4, so stay tuned for the results!