Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-4.1 nano
28
GPT-5.5 Pro
100
Pick GPT-5.5 Pro if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
Knowledge
+6.9 difference
GPT-4.1 nano
GPT-5.5 Pro
$0.1 / $0.4
$30 / $180
181 t/s
N/A
0.63s
N/A
1M
1M
Pick GPT-5.5 Pro if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
GPT-5.5 Pro is clearly ahead on the provisional aggregate, 100 to 28. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5 Pro's sharpest advantage is in knowledge, where it averages 57.2 against 50.3.
GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for GPT-4.1 nano. That is roughly 450.0x on output cost alone. GPT-5.5 Pro is the reasoning model in the pair, while GPT-4.1 nano 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-5.5 Pro is ahead on BenchLM's provisional leaderboard, 100 to 28.
GPT-5.5 Pro has the edge for knowledge tasks in this comparison, averaging 57.2 versus 50.3. GPT-4.1 nano stays close enough that the answer can still flip depending on your workload.
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