GPT-5.5 Pro is the stronger all-rounder.Claude Opus 4.5 is cheaper.
Scores updated · 9 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.
Claude Opus 4.5 costs 86% 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
- Extremely hard research-level math problemsFrontierMath Tier 4+73.2points ahead
- Unpublished advanced math problemsFrontierMath Tiers 1-3 (v2)+53.3points ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+53.1points ahead
Where Claude Opus 4.5 pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 9 tests both models report. The winning score is in its model's colour; marks a score checked independently.
ReasoningGPT-5.5 Pro
- ARC-AGI-2GPT-5.5 Pro by 46.637.684.2+46.6
- Humanity's Last ExamGPT-5.5 Pro by 27.130.157.2+27.1
- CritPtGPT-5.5 Pro by 264.630.6+26
MathGPT-5.5 Pro
- FrontierMath Tier 4GPT-5.5 Pro by 73.24.978+73.2
- FrontierMath Tiers 1-3 (v2)GPT-5.5 Pro by 53.334.487.7+53.3
Other results2 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.
- frontiermath_tier_4_v1GPT-5.5 Pro by 35.44.239.6+35.4
- ARC-AGI-1GPT-5.5 Pro by 138295+13
Questions people ask
Which is better, Claude Opus 4.5 or GPT-5.5 Pro?
GPT-5.5 Pro wins all four areas where both have results: agents, reasoning, facts and math. Claude Opus 4.5 wins none, but costs 86% less.
Which is cheaper?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; GPT-5.5 Pro costs $30.00 and $180.00. That makes Claude Opus 4.5 about 86% cheaper for the same work.
How do you compare the two?
We use the 9 benchmark tests both models have published scores on. The verdict counts the 7 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 2 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.