GPT-5.5 vs o3
Wins 8 of 8 areas
Coding · Agents · Reasoning · Facts · Images and charts · Math · Long documents · Following instructions
Wins 0 of 8 areas
—
GPT-5.5 is the stronger all-rounder.o3 is cheaper.
Scores updated · 27 tests both models report · How we compare
Where each one wins
Tests won in each of the eight areas we test. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking50GPT-5.55 of 5 tests
- FactsGetting facts right instead of making them up20GPT-5.52 of 3 tests · 1 tie
- CodingWriting and fixing software20GPT-5.52 of 2 tests
- AgentsCarrying out multi-step tasks on its own20GPT-5.52 of 2 tests
- Images and chartsUnderstanding pictures, charts and video21GPT-5.52 of 3 tests
- MathCompetition and research-level math10GPT-5.51 of 1 test
- Long documentsFinding answers in very long texts10GPT-5.51 of 1 test
- Following instructionsDoing exactly what it is asked10GPT-5.51 of 1 test
Math, long documents and following instructions 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.
o3 costs 71% 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 pulls ahead
- Abstract visual puzzles that people can solveARC-AGI-2+78.5points ahead
- Unpublished advanced math problemsFrontierMath Tiers 1-3 (v2)+52points ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+34.7points ahead
Where o3 pulls ahead
- Math problems shown in pictures and chartsMathVista+2.6points ahead
Every test, side by side
All 27 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGPT-5.5
- Terminal-Bench HardGPT-5.5 by 23.560.637.1+23.5
- SciCodeGPT-5.5 by 14.855.841+14.8
AgentsGPT-5.5
- BrowseCompGPT-5.5 by 34.784.449.7+34.7
- GDPValGPT-5.5 by 29.942.712.8+29.9
ReasoningGPT-5.5
- ARC-AGI-2GPT-5.5 by 78.5856.5+78.5
- CritPtGPT-5.5 by 2627.11.1+26
- Humanity's Last ExamGPT-5.5 by 25.745.820.1+25.7
- SimpleBenchGPT-5.5 by 15.96953.1+15.9
- GPQA DiamondGPT-5.5 by 10.893.582.7+10.8
FactsGPT-5.5
- AA-Omniscience · AccuracyGPT-5.5 by 19.45838.6+19.4
- SimpleQA VerifiedGPT-5.5 by 13.66349.4+13.6
- AA-Omniscience · Non-hallucinationtie1111.9tie
Images and chartsGPT-5.5
- MMMU-ProGPT-5.5 by 9.879.970.1+9.8
- LMArena · VisionGPT-5.5 by 78 rating points12921214+78 rating
- MathVistao3 by 2.684.286.8+2.6
Other results9 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.
- Artificial Analysis Coding IndexGPT-5.5 by 36.574.938.4+36.5
- AA-OmniscienceGPT-5.5 by 3620.5-15.6+36
- ARC-AGI-1GPT-5.5 by 34.29560.8+34.2
- frontiermath_tier_4_v1GPT-5.5 by 33.335.42.1+33.3
- FrontierMath (overall)GPT-5.5 by 19.635.415.8+19.6
- AA IntelligenceGPT-5.5 by 18.238.420.2+18.2
- τ²-Bench Telecom (AA run)GPT-5.5 by 13.293.980.7+13.2
- AA Agentic IndexGPT-5.5 by 1.237.336.1+1.2
- ERQAtie64.564tie
Questions people ask
Which is better, GPT-5.5 or o3?
GPT-5.5 wins all eight areas we test: coding, agents, reasoning, facts, images and charts, math, long documents and following instructions. o3 wins none, but costs 71% less.
Which is better for coding?
GPT-5.5. It wins 2 of the 2 coding tests both models report; o3 wins none.
Which is cheaper?
GPT-5.5 costs $5.00 per million input tokens and $30.00 per million output tokens; o3 costs $2.00 and $8.00. That makes o3 about 71% cheaper for the same work.
How do you compare the two?
We use the 27 benchmark tests both models have published scores on. The verdict counts the 18 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 9 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.