GPT-5.6 Luna vs GPT-6 Sol
Wins 0 of 8 areas
—
Wins 6 of 8 areas
Coding · Agents · Reasoning · Facts · Math · Following instructions
GPT-6 Sol is the stronger all-rounder.GPT-5.6 Luna is cheaper.
Scores updated · 36 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 thinking06GPT-6 Sol6 of 6 tests
- AgentsCarrying out multi-step tasks on its own03GPT-6 Sol3 of 3 tests
- FactsGetting facts right instead of making them up03GPT-6 Sol3 of 3 tests
- MathCompetition and research-level math03GPT-6 Sol3 of 3 tests
- CodingWriting and fixing software13GPT-6 Sol3 of 4 tests
- Following instructionsDoing exactly what it is asked01GPT-6 Sol1 of 1 test
- Images and chartsUnderstanding pictures, charts and video11Even1 each
- Long documentsFinding answers in very long texts00Even0 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-5.6 Luna costs 88% 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-6 Sol pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+32.5points ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+32.3points ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+31.5points ahead
Where GPT-5.6 Luna pulls ahead
- Programming problems, refreshed regularlyLiveBench · Coding+1.1points ahead
Every test, side by side
All 36 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGPT-6 Sol
- LMArena · WebDevGPT-6 Sol by 154 rating points15191673+154 rating
- LiveBench · Agentic CodingGPT-6 Sol by 4.548.452.9+4.5
- SciCodeGPT-6 Sol by 453.657.6+4
- LiveBench · CodingGPT-5.6 Luna by 1.182.981.8+1.1
AgentsGPT-6 Sol
- Terminal-Bench 4.0GPT-6 Sol by 32.311.643.9+32.3
- AA IT-Bench SREGPT-6 Sol by 9.140.349.4+9.1
- GDPValGPT-6 Sol by 2.44850.4+2.4
ReasoningGPT-6 Sol
- ARC-AGI-2GPT-6 Sol by 3059.689.6+30
- SimpleBenchGPT-6 Sol by 26.346.873.1+26.3
- CritPtGPT-6 Sol by 10.320.630.9+10.3
- Humanity's Last ExamGPT-6 Sol by 8.439.547.9+8.4
- ARC-AGI-3GPT-6 Sol by 4.40.24.6+4.4
- LiveBench · ReasoningGPT-6 Sol by 3.185.688.7+3.1
FactsGPT-6 Sol
- AA-Omniscience · Non-hallucinationGPT-6 Sol by 32.57.439.9+32.5
- SimpleQA VerifiedGPT-6 Sol by 19.74160.7+19.7
- AA-Omniscience · AccuracyGPT-6 Sol by 11.842.754.5+11.8
Images and chartsEven
- MMMU-ProGPT-6 Sol by 4.378.682.9+4.3
- LMArena · VisionGPT-5.6 Luna by 23 rating points12561233+23 rating
MathGPT-6 Sol
- FrontierMath Tier 4GPT-6 Sol by 31.558.590+31.5
- LiveBench · MathematicsGPT-6 Sol by 9.287.296.4+9.2
- FrontierMath Tiers 1-3 (v2)GPT-6 Sol by 7.782.189.8+7.7
Following instructionsGPT-6 Sol
- LiveBench · Instruction FollowingGPT-6 Sol by 8.560.168.6+8.5
Other results13 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-6 Sol by 37.4-10.327.1+37.4
- Terminal-Bench 4.0GPT-6 Sol by 32.117.349.4+32.1
- OSWorld 2.0GPT-6 Sol by 18.845.664.4+18.8
- livebench_languageGPT-6 Sol by 12.772.685.3+12.7
- AA IntelligenceGPT-6 Sol by 10.337.347.6+10.3
- Agents' Last ExamGPT-6 Sol by 6.150.356.4+6.1
- HealthBench Professional length-adjustedGPT-6 Sol by 5.155.760.8+5.1
- ARC-AGI-1GPT-6 Sol by 4.890.795.5+4.8
- livebench_data_analysisGPT-6 Sol by 3.27881.2+3.2
- HealthBench length-adjustedGPT-5.6 Luna by 2.655.853.2+2.6
- HealthBench Hard length-adjustedGPT-5.6 Luna by 1.93230.1+1.9
- DeepSWE 1.1GPT-6 Sol by 1.86768.8+1.8
- HealthBench Consensus length-adjustedGPT-6 Sol by 1.195.196.2+1.1
Questions people ask
Which is better, GPT-5.6 Luna or GPT-6 Sol?
GPT-6 Sol wins six of the eight areas we test: coding, agents, reasoning, facts, math and following instructions. GPT-5.6 Luna wins none, but costs 88% less. They are level on images and charts and long documents.
Which is better for coding?
GPT-6 Sol. It wins 3 of the 4 coding tests both models report; GPT-5.6 Luna wins 1.
Which is cheaper?
GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens; GPT-6 Sol costs $2.00 and $10.00. That makes GPT-5.6 Luna about 88% cheaper for the same work.
How do you compare the two?
We use the 36 benchmark tests both models have published scores on. The verdict counts the 23 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 13 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.