Gemini 3 Pro vs GPT-5.5

Pick GPT-5.5 if you want the stronger benchmark profile. Gemini 3 Pro only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.

GPT-5.5 is clearly ahead on the provisional aggregate, 89 to 83. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.5's sharpest advantage is in reasoning, where it averages 85 against 31.1. The single biggest benchmark swing on the page is ARC-AGI-2, 31.1% to 85%. Gemini 3 Pro does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $2.00 input / $12.00 output per 1M tokens for Gemini 3 Pro. That is roughly 2.5x on output cost alone. GPT-5.5 is the reasoning model in the pair, while Gemini 3 Pro is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Gemini 3 Pro gives you the larger context window at 2M, compared with 1M for GPT-5.5.