GPT-5.1 vs GPT-5.6 Sol
Wins 0 of 7 areas
—
Wins 6 of 7 areas
Coding · Agents · Reasoning · Facts · Images and charts · Long documents
GPT-5.6 Sol is the stronger all-rounder.GPT-5.1 is cheaper.
Scores updated · 39 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.
- ReasoningHard problems that need careful thinking05GPT-5.6 Sol5 of 5 tests
- CodingWriting and fixing software04GPT-5.6 Sol4 of 4 tests
- AgentsCarrying out multi-step tasks on its own03GPT-5.6 Sol3 of 3 tests
- Images and chartsUnderstanding pictures, charts and video02GPT-5.6 Sol2 of 2 tests
- FactsGetting facts right instead of making them up12GPT-5.6 Sol2 of 4 tests · 1 tie
- Long documentsFinding answers in very long texts01GPT-5.6 Sol1 of 1 test
- Following instructionsDoing exactly what it is asked00Even0 each · 1 tie
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 costs 53% 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-5.6 Sol pulls ahead
- Abstract visual puzzles that people can solveARC-AGI-2+74.9points ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+39.6points ahead
- Real work tasks from 44 professionsGDPVal+39.1points ahead
Where GPT-5.1 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+40.3points ahead
Every test, side by side
All 39 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGPT-5.6 Sol
- Terminal-Bench 2.1GPT-5.6 Sol by 35.652.488+35.6
- LMArena · WebDevGPT-5.6 Sol by 223 rating points13951618+223 rating
- Terminal-Bench HardGPT-5.6 Sol by 20.445.565.9+20.4
- SciCodeGPT-5.6 Sol by 13.843.357.1+13.8
AgentsGPT-5.6 Sol
- BrowseCompGPT-5.6 Sol by 39.650.890.4+39.6
- GDPValGPT-5.6 Sol by 39.116.555.6+39.1
- τ-Bench V3 · BankingGPT-5.6 Sol by 28.415.944.3+28.4
ReasoningGPT-5.6 Sol
- ARC-AGI-2GPT-5.6 Sol by 74.917.692.5+74.9
- CritPtGPT-5.6 Sol by 27.44.932.3+27.4
- Humanity's Last ExamGPT-5.6 Sol by 2128.549.5+21
- SimpleBenchGPT-5.6 Sol by 11.653.264.8+11.6
- GPQA DiamondGPT-5.6 Sol by 6.887.394.1+6.8
FactsGPT-5.6 Sol
- AA-Omniscience · Non-hallucinationGPT-5.1 by 40.348.17.8+40.3
- AA-Omniscience · AccuracyGPT-5.6 Sol by 21.737.759.4+21.7
- SimpleQA VerifiedGPT-5.6 Sol by 21.74869.7+21.7
- Vectara HHEM hallucination ratelower is bettertie12.112.4tie
Images and chartsGPT-5.6 Sol
- MMMU-ProGPT-5.6 Sol by 7.975.583.4+7.9
- LMArena · VisionGPT-5.6 Sol by 29 rating points12501279+29 rating
Other results19 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 (overall)GPT-5.6 Sol by 62.326.789+62.3
- AA Agentic IndexGPT-5.6 Sol by 28.921.650.5+28.9
- Artificial Analysis Coding IndexGPT-5.6 Sol by 2849.477.4+28
- ARC-AGI-1GPT-5.6 Sol by 23.772.896.5+23.7
- AA IntelligenceGPT-5.6 Sol by 22.324.747+22.3
- HLE (with tools)GPT-5.6 Sol by 21.842.764.5+21.8
- HealthBench Professional length-adjustedGPT-5.6 Sol by 20.939.660.5+20.9
- AA-OmniscienceGPT-5.6 Sol by 16.65.422+16.6
- vectara_avg_summary_lengthGPT-5.1 by 123.3 rating points254.4131.1+123.3 rating
- HealthBench Hard length-adjustedGPT-5.6 Sol by 7.725.433.1+7.7
- HealthBench length-adjustedGPT-5.6 Sol by 6.150.957+6.1
- τ²-Bench Telecom (AA run)GPT-5.6 Sol by 3.281.985.1+3.2
- vectara_answer_ratetie10099.1tie
- HealthBench Consensus length-adjustedtie9595.5tie
- vectara_factual_consistencytie87.987.6tie
- Image input eval - extremism (not_unsafe)tie11tie
- Image input eval - harms-erotic (not_unsafe)tie11tie
- Image input eval - hate (not_unsafe)tie11tie
- Image input eval - self-harm (not_unsafe)tie11tie
Questions people ask
Which is better, GPT-5.1 or GPT-5.6 Sol?
GPT-5.6 Sol wins six of the seven areas where both have results: coding, agents, reasoning, facts, images and charts and long documents. GPT-5.1 wins none, but costs 53% less. They are level on following instructions.
Which is better for coding?
GPT-5.6 Sol. It wins 4 of the 4 coding tests both models report; GPT-5.1 wins none.
Which is cheaper?
GPT-5.1 costs $1.25 per million input tokens and $10.00 per million output tokens; GPT-5.6 Sol costs $4.00 and $20.00. That makes GPT-5.1 about 53% cheaper for the same work.
How do you compare the two?
We use the 39 benchmark tests both models have published scores on. The verdict counts the 20 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 19 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.