Gemini 3.1 Pro vs GPT-5.4

Treat this as a split decision. Gemini 3.1 Pro makes more sense if multimodal & grounded is the priority or you want the cheaper token bill; GPT-5.4 is the better fit if you need the larger 1.05M context window or you want the stronger reasoning-first profile.

Gemini 3.1 Pro and GPT-5.4 finish on the same provisional overall score, so this is less about a single winner and more about where the edge shows up. The provisional headline says tie; the benchmark table is where the real choice happens.

GPT-5.4 is also the more expensive model on tokens at $2.50 input / $15.00 output per 1M tokens, versus $1.25 input / $5.00 output per 1M tokens for Gemini 3.1 Pro. That is roughly 3.0x on output cost alone. GPT-5.4 is the reasoning model in the pair, while Gemini 3.1 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. GPT-5.4 gives you the larger context window at 1.05M, compared with 1M for Gemini 3.1 Pro.