Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.5 Pro
100
o1-pro
30
Pick GPT-5.5 Pro if you want the stronger benchmark profile. o1-pro only becomes the better choice if knowledge is the priority.
Knowledge
+21.8 difference
GPT-5.5 Pro
o1-pro
$30 / $180
$150 / $600
N/A
N/A
N/A
N/A
1M
200K
Pick GPT-5.5 Pro if you want the stronger benchmark profile. o1-pro only becomes the better choice if knowledge is the priority.
GPT-5.5 Pro is clearly ahead on the provisional aggregate, 100 to 30. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
o1-pro is also the more expensive model on tokens at $150.00 input / $600.00 output per 1M tokens, versus $30.00 input / $180.00 output per 1M tokens for GPT-5.5 Pro. That is roughly 3.3x on output cost alone. GPT-5.5 Pro gives you the larger context window at 1M, compared with 200K for o1-pro.
GPT-5.5 Pro is ahead on BenchLM's provisional leaderboard, 100 to 30.
o1-pro has the edge for knowledge tasks in this comparison, averaging 79 versus 57.2. GPT-5.5 Pro stays close enough that the answer can still flip depending on your workload.
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