We evaluated OpenAI’s newly-released GPT 5 family of models and found that GPT 5 achieves SOTA performance for a fraction of the cost compared to similarly performing models.

Of the three, GPT 5 is the strongest model in the family with SOTA performance on public LegalBench and AIME benchmarks.

On private benchmarks, GPT 5 and GPT 5 Mini achieve top 10 performance on all but CaseLaw. Most notably, GPT 5 Mini is the new SOTA model on TaxEval at a substantially lower cost.

On public benchmarks, GPT 5 places top 5 and GPT 5 Mini places top 10 on nearly everything. Further, we found the two models have complementary strengths - GPT 5 is SOTA on LegalBench and AIME, while GPT 5 Mini is SOTA on LiveCodeBench.

Lastly, GPT 5 Nano achieves middle of the pack performance across the board. It narrowly places in the top 10 on AIME, compared to GPT 5 and GPT 5 Mini which top the charts.