Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Gemini 3 Pro Deep Think
86
GPT-5.5
89
Verified leaderboard positions: Gemini 3 Pro Deep Think unranked · GPT-5.5 #2
Pick GPT-5.5 if you want the stronger benchmark profile. Gemini 3 Pro Deep Think only becomes the better choice if you need the larger 2M context window.
Reasoning
+39.9 difference
Gemini 3 Pro Deep Think
GPT-5.5
$null / $null
$5 / $30
N/A
N/A
N/A
N/A
2M
1M
Pick GPT-5.5 if you want the stronger benchmark profile. Gemini 3 Pro Deep Think only becomes the better choice if you need the larger 2M context window.
GPT-5.5 has the cleaner provisional overall profile here, landing at 89 versus 86. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
GPT-5.5's sharpest advantage is in reasoning, where it averages 85 against 45.1. The single biggest benchmark swing on the page is ARC-AGI-2, 45.1% to 85%.
Gemini 3 Pro Deep Think gives you the larger context window at 2M, compared with 1M for GPT-5.5.
GPT-5.5 is ahead on BenchLM's provisional leaderboard, 89 to 86. The biggest single separator in this matchup is ARC-AGI-2, where the scores are 45.1% and 85%.
GPT-5.5 has the edge for reasoning in this comparison, averaging 85 versus 45.1. Inside this category, ARC-AGI-2 is the benchmark that creates the most daylight between them.
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