Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.5
89
o1
59
Verified leaderboard positions: GPT-5.5 #2 · o1 unranked
Pick GPT-5.5 if you want the stronger benchmark profile. o1 only becomes the better choice if knowledge is the priority.
Knowledge
+9.3 difference
GPT-5.5
o1
$5 / $30
$15 / $60
N/A
98 t/s
N/A
32.29s
1M
200K
Pick GPT-5.5 if you want the stronger benchmark profile. o1 only becomes the better choice if knowledge is the priority.
GPT-5.5 is clearly ahead on the provisional aggregate, 89 to 59. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
o1 is also the more expensive model on tokens at $15.00 input / $60.00 output per 1M tokens, versus $5.00 input / $30.00 output per 1M tokens for GPT-5.5. That is roughly 2.0x on output cost alone. GPT-5.5 gives you the larger context window at 1M, compared with 200K for o1.
GPT-5.5 is ahead on BenchLM's provisional leaderboard, 89 to 59. The biggest single separator in this matchup is GPQA, where the scores are 93.6% and 75.7%.
o1 has the edge for knowledge tasks in this comparison, averaging 75.7 versus 66.4. Inside this category, GPQA is the benchmark that creates the most daylight between them.
For engineers, researchers, and the plain curious — a weekly brief on new models, ranking shifts, and pricing changes.
Free. No spam. Unsubscribe anytime.