GPT-5.2 vs Step 3.5 Flash
Wins 6 of 7 areas
Coding · Reasoning · Facts · Math · Long documents · Following instructions
Wins 0 of 7 areas
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GPT-5.2 is the stronger all-rounder.Step 3.5 Flash is cheaper.
Scores updated · 26 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 software30GPT-5.23 of 3 tests
- ReasoningHard problems that need careful thinking30GPT-5.23 of 3 tests
- MathCompetition and research-level math20GPT-5.22 of 3 tests · 1 tie
- FactsGetting facts right instead of making them up20GPT-5.22 of 2 tests
- Long documentsFinding answers in very long texts10GPT-5.21 of 1 test
- Following instructionsDoing exactly what it is asked10GPT-5.21 of 1 test
- AgentsCarrying out multi-step tasks on its own11Even1 each
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.
Step 3.5 Flash costs 97% 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
- Reasons across sets of long documentsAA-LCR+32.7points ahead
- Real work tasks from 44 professionsGDPVal+20.7points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+20.7points ahead
Where Step 3.5 Flash pulls ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+3.2points ahead
Every test, side by side
All 26 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 19.74727.3+19.7
- SciCodeGPT-5.2 by 11.752.140.4+11.7
- SWE-bench VerifiedGPT-5.2 by 5.68074.4+5.6
AgentsEven
- GDPValGPT-5.2 by 20.748.327.6+20.7
- BrowseCompStep 3.5 Flash by 3.265.869+3.2
ReasoningGPT-5.2
- Humanity's Last ExamGPT-5.2 by 16.637.721.1+16.6
- CritPtGPT-5.2 by 9.111.62.5+9.1
- GPQA DiamondGPT-5.2 by 7.290.383.1+7.2
FactsGPT-5.2
- AA-Omniscience · AccuracyGPT-5.2 by 20.744.323.6+20.7
- AA-Omniscience · Non-hallucinationGPT-5.2 by 4.518.814.3+4.5
MathGPT-5.2
- HMMT Feb. 2026GPT-5.2 by 10.69786.4+10.6
- AIME 2026GPT-5.2 by 1.698.396.7+1.6
- IMOAnswerBenchtie86.385.4tie
Other results11 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.
- AA-OmniscienceGPT-5.2 by 40.9-0.9-41.8+40.9
- Artificial Analysis Coding IndexGPT-5.2 by 17.148.731.6+17.1
- AA IntelligenceGPT-5.2 by 13.830.416.6+13.8
- τ²-Bench Telecom (AA run)Step 3.5 Flash by 9.684.894.4+9.6
- AA Agentic IndexGPT-5.2 by 8.260.252+8.2
- Terminal-Bench 2.0GPT-5.2 by 35451+3
- AIME 2025GPT-5.2 by 2.710097.3+2.7
- τ²-BenchStep 3.5 Flash by 2.785.588.2+2.7
- MMLU-ProGPT-5.2 by 2.386.784.4+2.3
- HMMT Nov. 2025GPT-5.2 by 1.895.894+1.8
- HMMT Feb. 2025GPT-5.2 by 1.610098.4+1.6
Questions people ask
Which is better, GPT-5.2 or Step 3.5 Flash?
GPT-5.2 wins six of the seven areas where both have results: coding, reasoning, facts, math, long documents and following instructions. Step 3.5 Flash wins none, but costs 97% less. They are level on agents.
Which is better for coding?
GPT-5.2. It wins 3 of the 3 coding tests both models report; Step 3.5 Flash wins none.
Which is cheaper?
GPT-5.2 costs $1.75 per million input tokens and $14.00 per million output tokens; Step 3.5 Flash costs $0.10 and $0.30. That makes Step 3.5 Flash about 97% cheaper for the same work.
How do you compare the two?
We use the 26 benchmark tests both models have published scores on. The verdict counts the 15 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 11 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.