Enter opens the highlighted result. Esc closes.

GPT-5.6 Luna vs GPT-6 Sol

GPT-6 Sol leads GPT-5.6 Luna on coding, 76.0 to 58.0 on the Vibe Coding Index, and GPT-5.6 Luna costs 8.3x less per output token ($1.20 vs $10.00 per million). Updated October 22, 2026; 96 benchmarks have a result for both.

Replace GPT-5.6 Luna Replace GPT-6 Sol
GPT-5.6 LunaOpenAI
Coding
58.0
Overall
61.6
Output $/M
$1.20
38
GPT-6 SolOpenAI
Coding
76.0
Overall
74.6
Output $/M
$10.00
57
vs boards won of 96 shared, 1 tied

GPT-5.6 Luna or GPT-6 Sol: which to pick

Pick GPT-6 Sol for coding: it scores 76.0 on the Vibe Coding Index against 58.0 for GPT-5.6 Luna, though on 5 benchmarks against 6.

Pick GPT-5.6 Luna for output tokens 8.3x cheaper ($1.20 vs $10.00 per million) and work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.

Model AGPT-5.6 LunaOpenAI58.0/1006 independent benchmarks$0.04 per solved taskModel BGPT-6 SolOpenAI76.0/1005 independent benchmarksNo cost per solved task
Shared results
96
GPT-5.6 Luna only
23
GPT-6 Sol only
5
Like-for-like categories
8 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
GPT-5.6 Luna 58.0 from 6 benchmarks, GPT-6 Sol 76.0 from 5 benchmarks.
Widest category
Agentic work, 21.1 points apart on average over 13 shared benchmarks.
Widest single gap
Vending-Bench 2: GPT-5.6 Luna $4,095 against GPT-6 Sol $14,428, 64.6 points apart on a 0 to 100 scale.
Output price
GPT-5.6 Luna $1.20 against GPT-6 Sol $10.00 per million output tokens, 8.3x apart.
Context window
Both take 1.05M tokens.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryGPT-5.6 LunaBarsGPT-6 SolTies
Coding215
Intelligence02
Agentic work310
Reasoning49
Math24
Knowledge43
Web design09
General2351 tie
All shared boards38571 tie
CodingLike-for-likeSix of these boards feed the Vibe Coding Index215
Coding benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
LiveBench coding73.6%93.1%GPT-6 Sol
LMArena WebDev15181683GPT-6 Sol
AA Coding Index71.4Not measuredOnly GPT-5.6 Luna measured
SWE-bench Verified (Vals AI)93.0%Not measuredOnly GPT-5.6 Luna measured
Terminal-Bench 4 (Vals AI)11.6%44.4%GPT-6 Sol
Vibe Code Bench (Vals AI)77.1%87.8%GPT-6 Sol
Code migration (Vals AI)44.5%57.2%GPT-6 Sol
ProgramBench (Vals AI)0.0%2.0%GPT-6 Sol
IOI (Vals AI)61.8%82.6%GPT-6 Sol
Terminal-Bench 2.1 (Vals AI)79.0%83.2%GPT-6 Sol
Vibe Code Bench 1-100 (Vals AI)22.6%Not measuredOnly GPT-5.6 Luna measured
SkillsBench (Vals AI)60.5%Not measuredOnly GPT-5.6 Luna measured
CyberBench (Vals AI)73.6%78.0%GPT-6 Sol
SciCode53.6%57.6%GPT-6 Sol
FrontierCode39.8%49.3%GPT-6 Sol
WeirdML60.9%Not measuredOnly GPT-5.6 Luna measured
ALE-Bench1667.42462.0GPT-6 Sol
LMArena Text: coding14661448GPT-5.6 Luna
LMArena Text: software and IT14631433GPT-5.6 Luna
LMArena WebDev: React15081685GPT-6 Sol
LMArena WebDev: HTML15201685GPT-6 Sol
LMArena WebDev: from an image15171660GPT-6 Sol
SciCode6.2%Not measuredOnly GPT-5.6 Luna measured
Neither model has a result on the other 16 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
Intelligence benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
AA Intelligence Index37.347.6GPT-6 Sol
Epoch Capabilities Index156.5163.7GPT-6 Sol
Agentic workLike-for-likePublic boards, shown as published, kept out of the index310
Agentic work benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
AA Agentic Index42.1Not measuredOnly GPT-5.6 Luna measured
Design Arena: agents building web appsNot measured1231Only GPT-6 Sol measured
Design Arena: agents building full-stack appsNot measured1238Only GPT-6 Sol measured
Design Arena: agents building mobile appsNot measured1217Only GPT-6 Sol measured
LiveBench research51.0%69.3%GPT-6 Sol
LiveBench browser68.0%92.0%GPT-6 Sol
LiveBench long agentic30.4%66.9%GPT-6 Sol
SREBench (Vals AI)1.5%30.5%GPT-6 Sol
Finance Agent (Vals AI)55.0%49.0%GPT-5.6 Luna
Tax Agent Bench (Vals AI)24.8%15.0%GPT-5.6 Luna
Legal Research Bench (Vals AI)36.5%28.9%GPT-5.6 Luna
Excel Modeling Benchmark (Vals AI)67.1%71.5%GPT-6 Sol
BioMysteryBench (Vals AI)61.5%74.8%GPT-6 Sol
Terminal-Bench-Science (Vals AI)0.0%30.0%GPT-6 Sol
Vals Science Index25.3%45.0%GPT-6 Sol
APEX-Agents43.0%54.3%GPT-6 Sol
BALROG45.6%Not measuredOnly GPT-5.6 Luna measured
SpireClimbNot measured7.5%Only GPT-6 Sol measured
Vending-Bench 2$4,095$14,428GPT-6 Sol
Neither model has a result on the other 22 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index49
Reasoning benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
GPQA Diamond91.7%Not measuredOnly GPT-5.6 Luna measured
LiveBench reasoning85.6%88.7%GPT-6 Sol
MysteryMechanism (Vals AI)14.4%30.2%GPT-6 Sol
MMMU Pro (Vals AI)85.0%Not measuredOnly GPT-5.6 Luna measured
GPQA Diamond (Artificial Analysis run)91.1%Not measuredOnly GPT-5.6 Luna measured
Humanity's Last Exam (Artificial Analysis run)39.5%47.9%GPT-6 Sol
GPQA Diamond (Epoch AI run)91.6%94.3%GPT-6 Sol
ARC-AGI88.0%95.5%GPT-6 Sol
ARC-AGI-259.5%89.6%GPT-6 Sol
SimpleBench46.8%Not measuredOnly GPT-5.6 Luna measured
Chess puzzles43.0%56.0%GPT-6 Sol
Mystery game puzzles21.0%56.0%GPT-6 Sol
EBR-benchNot measured53.3%Only GPT-6 Sol measured
LMArena Text: hard prompts14511422GPT-5.6 Luna
LMArena Text: expert14781437GPT-5.6 Luna
LMArena Text: hard prompts in English14601420GPT-5.6 Luna
LMArena Vision: diagrams12731270GPT-5.6 Luna
LMArena Vision: homework12821286GPT-6 Sol
Kagi LLM Benchmark49.1%Not measuredOnly GPT-5.6 Luna measured
Neither model has a result on the other 3 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index24
Math benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
OTIS Mock AIME98.3%100.0%GPT-6 Sol
FrontierMath, tiers 1 to 382.1%89.8%GPT-6 Sol
FrontierMath, tier 461.0%90.0%GPT-6 Sol
ProofBench60.0%83.0%GPT-6 Sol
LMArena Text: math14591407GPT-5.6 Luna
LMArena Text: mathematical work14701424GPT-5.6 Luna
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index43
Knowledge benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
MMLU Pro86.0%Not measuredOnly GPT-5.6 Luna measured
LegalBench (Vals AI)84.0%Not measuredOnly GPT-5.6 Luna measured
CorpFin (Vals AI)64.2%Not measuredOnly GPT-5.6 Luna measured
TaxEval (Vals AI)76.2%Not measuredOnly GPT-5.6 Luna measured
MortgageTax (Vals AI)67.3%Not measuredOnly GPT-5.6 Luna measured
MedCode (Vals AI)42.4%47.1%GPT-6 Sol
SimpleQA Verified41.0%60.7%GPT-6 Sol
LMArena Text: science14331389GPT-5.6 Luna
LMArena Text: medicine and healthcare13991366GPT-5.6 Luna
LMArena Text: legal and government14461396GPT-5.6 Luna
LMArena Text: business and finance14391380GPT-5.6 Luna
FACTS Benchmark Suite35.0%72.5%GPT-6 Sol
Neither model has a result on the other 6 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index09
Web design benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
Design Arena: websites12551292GPT-6 Sol
Design Arena: UI components12481290GPT-6 Sol
Design Arena: game dev11941311GPT-6 Sol
Design Arena: data viz12111269GPT-6 Sol
Design Arena: 3D11211314GPT-6 Sol
Design Arena: all code categories12311300GPT-6 Sol
Design Arena: SVG11941315GPT-6 Sol
Design Arena: ASCII art11421222GPT-6 Sol
LiveBench design76.0%82.2%GPT-6 Sol
GeneralLike-for-likePublic boards, shown as published, kept out of the index235
General benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
LiveBench data analysis78.0%81.2%GPT-6 Sol
Public Benefits Bench (Vals AI)61.2%56.6%GPT-5.6 Luna
SAGE (Vals AI)44.2%44.8%GPT-6 Sol
MedScribe (Vals AI)84.4%82.0%GPT-5.6 Luna
Vals Multimodal Index69.1%Not measuredOnly GPT-5.6 Luna measured
Long context reasoning (AA-LCR)83.7%83.7%Tie
DTBench89.1%97.3%GPT-6 Sol
LMCA48.5%59.1%GPT-6 Sol
Surface Evolver Bench61.9%Not measuredOnly GPT-5.6 Luna measured
Furniture assembly42.5%58.3%GPT-6 Sol
LMArena Text14311398GPT-5.6 Luna
LMArena Text: instruction following14371413GPT-5.6 Luna
LMArena Text: creative writing13961378GPT-5.6 Luna
LMArena Vision12571240GPT-5.6 Luna
LMArena Text: English14411396GPT-5.6 Luna
LMArena Text: non-English14171388GPT-5.6 Luna
LMArena Text: Chinese14701412GPT-5.6 Luna
LMArena Text: German14551379GPT-5.6 Luna
LMArena Text: Japanese14151377GPT-5.6 Luna
LMArena Text: Korean14151336GPT-5.6 Luna
LMArena Text: French14581399GPT-5.6 Luna
LMArena Text: Spanish14461387GPT-5.6 Luna
LMArena Text: Russian14271402GPT-5.6 Luna
LMArena Text: Polish14051372GPT-5.6 Luna
LMArena Text: multi-turn14341414GPT-5.6 Luna
LMArena Text: longer queries14361416GPT-5.6 Luna
LMArena Text: writing and language14191389GPT-5.6 Luna
LMArena Text: entertainment and media14021373GPT-5.6 Luna
LMArena Vision: English12631229GPT-5.6 Luna
LMArena Vision: Chinese1294Not measuredOnly GPT-5.6 Luna measured
LMArena Vision: reading text12641258GPT-5.6 Luna
LMArena Vision: humor1190Not measuredOnly GPT-5.6 Luna measured
LMArena Vision: creative writing12571219GPT-5.6 Luna
LMArena Document1457Not measuredOnly GPT-5.6 Luna measured
Neither model has a result on the other 12 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for GPT-5.6 Luna and GPT-6 Sol
BenchmarkGPT-5.6 LunaGPT-6 SolLeader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

GPT-5.6 Luna$0.0008Fits in one request
GPT-6 Sol$0.0070Fits in one request

GPT-5.6 Luna costs less

Repository review

50K input + 3K output tokens

GPT-5.6 Luna$0.014Fits in one request
GPT-6 Sol$0.130Fits in one request

GPT-5.6 Luna costs less

Agent loop

200K input + 10K output tokens

GPT-5.6 Luna$0.052Fits in one request
GPT-6 Sol$0.500Fits in one request

GPT-5.6 Luna costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of GPT-5.6 Luna and GPT-6 Sol
SpecificationOpenAI GPT-5.6 LunaOpenAI GPT-6 Sol
MakerOpenAIOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedJuly 9, 2026September 22, 2026
Context window1.05M1.05M
Input $/Mtok$0.20$2.00
Output $/Mtok$1.20$10.00
Coding index58.076.0
Independent measurements behind it65
Cost per solved task$0.04Not computable
SourceOpenRouter listingOpenRouter listing

Questions

Is GPT-5.6 Luna better than GPT-6 Sol for coding?

Pick GPT-6 Sol for coding: it scores 76.0 on the Vibe Coding Index against 58.0 for GPT-5.6 Luna, though on 5 benchmarks against 6. Pick GPT-5.6 Luna for output tokens 8.3x cheaper ($1.20 vs $10.00 per million) and work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.

Which is cheaper, GPT-5.6 Luna or GPT-6 Sol?

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. Cost per solved task is known for GPT-5.6 Luna only.

Which has the bigger context window, GPT-5.6 Luna or GPT-6 Sol?

Neither: both take 1.05M tokens.

How many benchmarks is the GPT-5.6 Luna vs GPT-6 Sol comparison based on?

96 benchmarks have a result for both models as of October 22, 2026. GPT-5.6 Luna's coding index rests on 6 independent benchmarks and GPT-6 Sol's on 5. Where only one model has a result, the page says so instead of naming a winner.

Compare next

Embed this comparison on your site

Free under CC BY 4.0, while the source link stays visible. Preview the frame · Terms and other embeds

<iframe src="https://llmbenchmark.ai/embed/compare/gpt-5-6-luna-vs-gpt-6-sol" title="GPT-5.6 Luna vs GPT-6 Sol, LLMBenchmark.ai" width="100%" height="360" style="border:0;max-width:100%" loading="lazy"></iframe>
<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/gpt-5-6-luna-vs-gpt-6-sol">LLMBenchmark.ai, GPT-5.6 Luna vs GPT-6 Sol</a></p>