Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-4.1 nano
27
GPT-5.5
91
Verified leaderboard positions: GPT-4.1 nano unranked · GPT-5.5 #5
Pick GPT-5.5 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
+16.1 difference
GPT-4.1 nano
GPT-5.5
$0.1 / $0.4
$5 / $30
181 t/s
N/A
0.63s
N/A
1M
1M
Pick GPT-5.5 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 is clearly ahead on the provisional aggregate, 91 to 27. 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 knowledge, where it averages 66.4 against 50.3. The single biggest benchmark swing on the page is GPQA, 50.3% to 93.6%.
GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for GPT-4.1 nano. That is roughly 75.0x on output cost alone. GPT-5.5 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 is ahead on BenchLM's provisional leaderboard, 91 to 27. The biggest single separator in this matchup is GPQA, where the scores are 50.3% and 93.6%.
GPT-5.5 has the edge for knowledge tasks in this comparison, averaging 66.4 versus 50.3. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.
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