GPT-5.5 Pro is the stronger all-rounder.GPT-5.5 is cheaper.
Scores updated · 14 tests both models report · How we compare
Where each one wins
Tests won in each of the four areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
Agents and facts rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
GPT-5.5 costs 83% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where GPT-5.5 Pro pulls ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+11.4points ahead
- Common-sense trick questionsSimpleBench+7.9points ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+5.7points ahead
Where GPT-5.5 pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 14 tests both models report. The winning score is in its model's colour; marks a score checked independently.
ReasoningGPT-5.5 Pro
- Humanity's Last ExamGPT-5.5 Pro by 11.445.857.2+11.4
- SimpleBenchGPT-5.5 Pro by 7.96976.9+7.9
- CritPtGPT-5.5 Pro by 3.527.130.6+3.5
- ARC-AGI-2tie8584.2tie
MathGPT-5.5 Pro
- FrontierMath Tier 4GPT-5.5 Pro by 5.672.578+5.6
- FrontierMath Tiers 1-3 (v2)GPT-5.5 Pro by 2.485.387.7+2.4
Other results6 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- GeneBenchGPT-5.5 Pro by 8.22533.2+8.2
- FrontierMath (overall)GPT-5.5 Pro by 4.235.439.6+4.2
- frontiermath_tier_4_v1GPT-5.5 Pro by 4.235.439.6+4.2
- DNA sequence design for transcription factor bindingGPT-5.5 Pro by 2.713.816.5+2.7
- Hard-negative protein binding predictionGPT-5.5 by 1.51.50+1.5
- ARC-AGI-1tie9595tie
Questions people ask
Which is better, GPT-5.5 or GPT-5.5 Pro?
GPT-5.5 Pro wins all four areas where both have results: agents, reasoning, facts and math. GPT-5.5 wins none, but costs 83% less.
Which is cheaper?
GPT-5.5 costs $5.00 per million input tokens and $30.00 per million output tokens; GPT-5.5 Pro costs $30.00 and $180.00. That makes GPT-5.5 about 83% cheaper for the same work.
How do you compare the two?
We use the 14 benchmark tests both models have published scores on. The verdict counts the 8 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 6 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.