GPT-5.1 Codex vs GPT-5.2
Wins 0 of 7 areas
—
Wins 6 of 7 areas
Coding · Agents · Reasoning · Images and charts · Long documents · Following instructions
GPT-5.2 is the stronger all-rounder.GPT-5.1 Codex is cheaper.
Scores updated · 20 tests both models report · How we compare
Where each one wins
Tests won in each of the seven 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.
- CodingWriting and fixing software04GPT-5.24 of 4 tests
- ReasoningHard problems that need careful thinking03GPT-5.23 of 3 tests
- AgentsCarrying out multi-step tasks on its own01GPT-5.21 of 1 test
- Images and chartsUnderstanding pictures, charts and video01GPT-5.21 of 1 test
- Long documentsFinding answers in very long texts01GPT-5.21 of 1 test
- Following instructionsDoing exactly what it is asked01GPT-5.21 of 1 test
- FactsGetting facts right instead of making them up11Even1 each
Agents, images and charts, 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.
GPT-5.1 Codex costs 29% 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-5.2 pulls ahead
- Real work tasks from 44 professionsGDPVal+13.7points ahead
- Reasons across sets of long documentsAA-LCR+13.4points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+12.2points ahead
Where GPT-5.1 Codex pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+4points ahead
Every test, side by side
All 20 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGPT-5.2
- Terminal-Bench HardGPT-5.2 by 12.234.847+12.2
- SciCodeGPT-5.2 by 11.940.252.1+11.9
- LMArena · WebDevGPT-5.2 by 80 rating points13361416+80 rating
- SWE-bench VerifiedGPT-5.2 by 6.373.780+6.3
ReasoningGPT-5.2
- Humanity's Last ExamGPT-5.2 by 1225.737.7+12
- CritPtGPT-5.2 by 5.95.711.6+5.9
- GPQA DiamondGPT-5.2 by 4.38690.3+4.3
FactsEven
- AA-Omniscience · AccuracyGPT-5.2 by 4.439.944.3+4.4
- AA-Omniscience · Non-hallucinationGPT-5.1 Codex by 422.818.8+4
Other results7 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-5.2 by 12.136.648.7+12.1
- AA Agentic IndexGPT-5.2 by 9.550.760.2+9.5
- AA IntelligenceGPT-5.2 by 6.723.730.4+6.7
- AA-OmniscienceGPT-5.2 by 5.6-6.5-0.9+5.6
- swe_bench_bashGPT-5.2 by 36669+3
- τ²-Bench Telecom (AA run)GPT-5.2 by 1.88384.8+1.8
- Terminal-Bench 2.0GPT-5.2 by 1.252.854+1.2
Questions people ask
Which is better, GPT-5.1 Codex or GPT-5.2?
GPT-5.2 wins six of the seven areas where both have results: coding, agents, reasoning, images and charts, long documents and following instructions. GPT-5.1 Codex wins none, but costs 29% less. They are level on facts.
Which is better for coding?
GPT-5.2. It wins 4 of the 4 coding tests both models report; GPT-5.1 Codex wins none.
Which is cheaper?
GPT-5.1 Codex costs $1.25 per million input tokens and $10.00 per million output tokens; GPT-5.2 costs $1.75 and $14.00. That makes GPT-5.1 Codex about 29% cheaper for the same work.
How do you compare the two?
We use the 20 benchmark tests both models have published scores on. The verdict counts the 13 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 7 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.