GPT-6 Luna vs o3
GPT-6 Luna leads o3 on the Artificial Analysis Intelligence Index, 38.1 to 20.2, and GPT-6 Luna costs 16.0x less per output token ($0.50 vs $8.00 per million). Updated October 22, 2026; 59 benchmarks have a result for both.
GPT-6 Luna or o3: which to pick
Only GPT-6 Luna has a coding score, 57.3 on the Vibe Coding Index; o3 has none, so the two cannot be ranked on coding.
Pick o3 for work measured by Chess puzzles or Mystery game puzzles, where it leads.
- Shared results
- 59
- GPT-6 Luna only
- 44
- o3 only
- 43
- Like-for-like categories
- 7 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.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Only GPT-6 Luna has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
GPT-6 Luna
GPT-6 Luna leads, 38.1 against 20.2.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only o3 has a GPQA Diamond result, 84.1%.
Directional only
Math
AIME
No call
Only o3 has a AIME result, 85.3%.
Directional only
Knowledge
MMLU Pro
No call
Only o3 has a MMLU Pro result, 85.6%.
Directional only
Web design
Design Arena: websites
GPT-6 Luna
GPT-6 Luna leads, 1271 against 1036.
Same board, both measured
General
Vals Index
No call
Only GPT-6 Luna has a Vals Index result, 52.3%.
Directional only
Long documents
Listed context window
GPT-6 Luna
GPT-6 Luna takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-6 Luna
GPT-6 Luna $0.0003, o3 $0.0060 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only o3 has the number, $0.571.
Directional only
At a glance
- Coding index
- GPT-6 Luna 57.3 from 5 benchmarks, o3 not benchmarked.
- Widest category
- Web design, 25.1 points apart on average over 5 shared benchmarks.
- Widest single gap
- ARC-AGI-2: GPT-6 Luna 59.3% against o3 6.5%, 52.8 points apart on a 0 to 100 scale.
- Output price
- GPT-6 Luna $0.50 against o3 $8.00 per million output tokens, 16.0x apart.
- Context window
- GPT-6 Luna takes 1.05M tokens, o3 200K.
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.
| Category | GPT-6 Luna | Bars | o3 | Ties |
|---|---|---|---|---|
| Coding | 3 | 0 | ||
| Intelligence | 2 | 0 | ||
| Reasoning | 8 | 3 | ||
| Math | 3 | 1 | ||
| Knowledge | 1 | 6 | ||
| Web design | 5 | 0 | ||
| General | 13 | 14 | ||
| All shared boards | 35 | 24 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index30
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 81.3% | Only o3 measured |
| SWE-bench Verified | Not measured | 58.4% | Only o3 measured |
| SWE-bench Multimodal | Not measured | 36.0% | Only o3 measured |
| LiveBench coding | 84.5% | Not measured | Only GPT-6 Luna measured |
| LMArena WebDev | 1578 | Not measured | Only GPT-6 Luna measured |
| LiveCodeBench (Vals AI) | Not measured | 83.9% | Only o3 measured |
| Terminal-Bench 4 (Vals AI) | 13.6% | Not measured | Only GPT-6 Luna measured |
| Vibe Code Bench (Vals AI) | 81.7% | Not measured | Only GPT-6 Luna measured |
| Code migration (Vals AI) | 42.5% | Not measured | Only GPT-6 Luna measured |
| ProgramBench (Vals AI) | 0.5% | Not measured | Only GPT-6 Luna measured |
| IOI (Vals AI) | 55.6% | Not measured | Only GPT-6 Luna measured |
| Terminal-Bench 2.1 (Vals AI) | 73.0% | Not measured | Only GPT-6 Luna measured |
| SWE-bench Multimodal (Vals AI) | 37.5% | Not measured | Only GPT-6 Luna measured |
| CyberBench (Vals AI) | 76.3% | Not measured | Only GPT-6 Luna measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 80.8% | Only o3 measured |
| SciCode | 54.6% | Not measured | Only GPT-6 Luna measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 37.1% | Only o3 measured |
| FrontierCode | 42.4% | Not measured | Only GPT-6 Luna measured |
| GSO-Bench | Not measured | 8.8% | Only o3 measured |
| WeirdML | Not measured | 52.4% | Only o3 measured |
| ALE-Bench | 1576.9 | 933.5 | GPT-6 Luna |
| LMArena Text: coding | 1437 | 1407 | GPT-6 Luna |
| LMArena Text: software and IT | 1423 | 1415 | GPT-6 Luna |
| LMArena WebDev: React | 1573 | Not measured | Only GPT-6 Luna measured |
| LMArena WebDev: HTML | 1595 | Not measured | Only GPT-6 Luna measured |
| LMArena WebDev: from an image | 1571 | Not measured | Only GPT-6 Luna measured |
| SciCode | Not measured | 9.2% | Only o3 measured |
| Neither model has a result on the other 12 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.1 | 20.2 | GPT-6 Luna |
| Epoch Capabilities Index | 156.8 | 146.7 | GPT-6 Luna |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index24 boards, none shared
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1191 | Not measured | Only GPT-6 Luna measured |
| Design Arena: agents building full-stack apps | 1158 | Not measured | Only GPT-6 Luna measured |
| Design Arena: agents building mobile apps | 1134 | Not measured | Only GPT-6 Luna measured |
| LiveBench research | 43.5% | Not measured | Only GPT-6 Luna measured |
| LiveBench browser | 72.0% | Not measured | Only GPT-6 Luna measured |
| LiveBench long agentic | 48.1% | Not measured | Only GPT-6 Luna measured |
| SREBench (Vals AI) | 2.7% | Not measured | Only GPT-6 Luna measured |
| Finance Agent (Vals AI) | 49.9% | Not measured | Only GPT-6 Luna measured |
| Tax Agent Bench (Vals AI) | 19.9% | Not measured | Only GPT-6 Luna measured |
| Legal Research Bench (Vals AI) | 30.3% | Not measured | Only GPT-6 Luna measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 4.2% | Not measured | Only GPT-6 Luna measured |
| Excel Modeling Benchmark (Vals AI) | 68.5% | Not measured | Only GPT-6 Luna measured |
| BioMysteryBench (Vals AI) | 61.5% | Not measured | Only GPT-6 Luna measured |
| Terminal-Bench-Science (Vals AI) | 4.3% | Not measured | Only GPT-6 Luna measured |
| Vals Science Index | 28.4% | Not measured | Only GPT-6 Luna measured |
| τ²-Bench Telecom | Not measured | 80.7% | Only o3 measured |
| APEX-Agents | 44.3% | Not measured | Only GPT-6 Luna measured |
| METR time horizons | Not measured | 65.4% | Only o3 measured |
| GDPval | Not measured | 30.8% | Only o3 measured |
| DeepResearch Bench | Not measured | 45.2% | Only o3 measured |
| OSWorld | Not measured | 23.0% | Only o3 measured |
| SpireClimb | 0.0% | Not measured | Only GPT-6 Luna measured |
| Berkeley Function Calling Leaderboard (BFCL) | Not measured | 63.0% | Only o3 measured |
| BrowseComp-Plus | Not measured | 65.9% | Only o3 measured |
| Neither model has a result on the other 17 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index83
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 84.1% | Only o3 measured |
| LiveBench reasoning | 81.8% | Not measured | Only GPT-6 Luna measured |
| MysteryMechanism (Vals AI) | 19.4% | Not measured | Only GPT-6 Luna measured |
| MMMU Pro (Vals AI) | Not measured | 80.4% | Only o3 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 82.7% | Only o3 measured |
| Humanity's Last Exam (Artificial Analysis run) | 38.5% | 20.1% | GPT-6 Luna |
| GPQA Diamond (Epoch AI run) | 90.5% | 81.8% | GPT-6 Luna |
| ARC-AGI | 86.7% | 60.8% | GPT-6 Luna |
| ARC-AGI-2 | 59.3% | 6.5% | GPT-6 Luna |
| SimpleBench | Not measured | 53.1% | Only o3 measured |
| Chess puzzles | 36.0% | 37.0% | o3 |
| Mystery game puzzles | 7.0% | 29.0% | o3 |
| VPCT | Not measured | 52.0% | Only o3 measured |
| LMArena Text: hard prompts | 1410 | 1402 | GPT-6 Luna |
| LMArena Text: expert | 1442 | 1402 | GPT-6 Luna |
| LMArena Text: hard prompts in English | 1410 | 1411 | o3 |
| LMArena Vision: diagrams | 1245 | 1220 | GPT-6 Luna |
| LMArena Vision: homework | 1261 | 1234 | GPT-6 Luna |
| Kagi LLM Benchmark | Not measured | 67.6% | Only o3 measured |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index31
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| AIME | Not measured | 85.3% | Only o3 measured |
| MATH 500 (Vals AI) | Not measured | 94.6% | Only o3 measured |
| MGSM (Vals AI) | Not measured | 91.8% | Only o3 measured |
| AA Math Index | Not measured | 88.3 | Only o3 measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 88.3% | Only o3 measured |
| OTIS Mock AIME | 98.9% | 84.4% | GPT-6 Luna |
| FrontierMath, tiers 1 to 3 | 78.9% | 33.3% | GPT-6 Luna |
| FrontierMath, tier 4 | 56.1% | Not measured | Only GPT-6 Luna measured |
| ProofBench | 64.0% | Not measured | Only GPT-6 Luna measured |
| MATH level 5 | Not measured | 97.8% | Only o3 measured |
| LMArena Text: math | 1409 | 1426 | o3 |
| LMArena Text: mathematical work | 1427 | 1423 | GPT-6 Luna |
| Neither model has a result on the other 1 board here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index16
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 85.6% | Only o3 measured |
| LegalBench (Vals AI) | Not measured | 83.8% | Only o3 measured |
| CorpFin (Vals AI) | Not measured | 59.7% | Only o3 measured |
| TaxEval (Vals AI) | Not measured | 74.6% | Only o3 measured |
| MortgageTax (Vals AI) | Not measured | 65.7% | Only o3 measured |
| MedQA (Vals AI) | Not measured | 96.1% | Only o3 measured |
| MedCode (Vals AI) | 44.7% | 47.3% | o3 |
| MMLU Pro (Artificial Analysis run) | Not measured | 85.3% | Only o3 measured |
| SimpleQA Verified | 41.4% | 49.4% | o3 |
| GeoBench | Not measured | 74.0% | Only o3 measured |
| LMArena Text: science | 1386 | 1429 | o3 |
| LMArena Text: medicine and healthcare | 1352 | 1448 | o3 |
| LMArena Text: legal and government | 1400 | 1428 | o3 |
| LMArena Text: business and finance | 1388 | 1393 | o3 |
| FACTS Benchmark Suite | 63.3% | 44.4% | GPT-6 Luna |
| Neither model has a result on the other 3 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| Design Arena: websites | 1271 | 1036 | GPT-6 Luna |
| Design Arena: UI components | 1295 | 1017 | GPT-6 Luna |
| Design Arena: game dev | 1257 | 1034 | GPT-6 Luna |
| Design Arena: data viz | 1216 | 1200 | GPT-6 Luna |
| Design Arena: 3D | 1218 | Not measured | Only GPT-6 Luna measured |
| Design Arena: all code categories | 1270 | 1020 | GPT-6 Luna |
| Design Arena: SVG | 1252 | Not measured | Only GPT-6 Luna measured |
| Design Arena: ASCII art | 1153 | Not measured | Only GPT-6 Luna measured |
| LiveBench design | 82.5% | Not measured | Only GPT-6 Luna measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index1314
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| Vals Index | 52.3% | Not measured | Only GPT-6 Luna measured |
| LiveBench data analysis | 73.4% | Not measured | Only GPT-6 Luna measured |
| Public Benefits Bench (Vals AI) | 57.6% | Not measured | Only GPT-6 Luna measured |
| SAGE (Vals AI) | 48.1% | 41.8% | GPT-6 Luna |
| MedScribe (Vals AI) | 83.7% | 76.7% | GPT-6 Luna |
| IFBench | Not measured | 71.4% | Only o3 measured |
| Long context reasoning (AA-LCR) | 83.3% | 74.7% | GPT-6 Luna |
| DTBench | 90.1% | 84.8% | GPT-6 Luna |
| LMCA | 44.5% | 39.7% | GPT-6 Luna |
| Fiction.LiveBench | Not measured | 88.9% | Only o3 measured |
| Creative writing (Lech Mazur) | Not measured | 83.9% | Only o3 measured |
| CL-bench | Not measured | 17.8% | Only o3 measured |
| Furniture assembly | 44.2% | Not measured | Only GPT-6 Luna measured |
| LMArena Text | 1389 | 1410 | o3 |
| LMArena Text: instruction following | 1408 | 1368 | GPT-6 Luna |
| LMArena Text: creative writing | 1363 | 1359 | GPT-6 Luna |
| LMArena Vision | 1216 | 1214 | GPT-6 Luna |
| LMArena Text: English | 1393 | 1417 | o3 |
| LMArena Text: non-English | 1381 | 1401 | o3 |
| LMArena Text: Chinese | 1427 | 1437 | o3 |
| LMArena Text: German | 1376 | 1420 | o3 |
| LMArena Text: Japanese | 1369 | 1403 | o3 |
| LMArena Text: Korean | 1359 | 1370 | o3 |
| LMArena Text: French | 1408 | 1430 | o3 |
| LMArena Text: Spanish | 1391 | 1395 | o3 |
| LMArena Text: Russian | 1392 | 1406 | o3 |
| LMArena Text: Polish | 1383 | 1438 | o3 |
| LMArena Text: multi-turn | 1392 | 1405 | o3 |
| LMArena Text: longer queries | 1408 | 1372 | GPT-6 Luna |
| LMArena Text: writing and language | 1384 | 1372 | GPT-6 Luna |
| LMArena Text: entertainment and media | 1364 | 1373 | o3 |
| LMArena Vision: English | 1204 | 1221 | o3 |
| LMArena Vision: Chinese | 1266 | 1237 | GPT-6 Luna |
| LMArena Vision: reading text | 1225 | 1218 | GPT-6 Luna |
| LMArena Vision: humor | Not measured | 1222 | Only o3 measured |
| LMArena Vision: captioning | Not measured | 1210 | Only o3 measured |
| LMArena Vision: recognizing things | Not measured | 1234 | Only o3 measured |
| LMArena Vision: creative writing | 1205 | 1201 | GPT-6 Luna |
| Neither model has a result on the other 8 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-6 Luna | o3 | Leader |
|---|---|---|---|
| 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-6 Luna costs less
Repository review
50K input + 3K output tokens
GPT-6 Luna costs less
Agent loop
200K input + 10K output tokens
GPT-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.
| Specification | OpenAI GPT-6 Luna | OpenAI o3 |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | September 22, 2026 | April 16, 2025 |
| Context window | 1.05M | 200K |
| Input $/Mtok | $0.10 | $2.00 |
| Output $/Mtok | $0.50 | $8.00 |
| Coding index | 57.3 | Not benchmarked |
| Independent measurements behind it | 5 | 0 |
| Cost per solved task | Not computable | $0.571 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-6 Luna better than o3 for coding?
Only GPT-6 Luna has a coding score, 57.3 on the Vibe Coding Index; o3 has none, so the two cannot be ranked on coding. Pick o3 for work measured by Chess puzzles or Mystery game puzzles, where it leads.
Which is cheaper, GPT-6 Luna or o3?
GPT-6 Luna costs $0.10 per million input tokens and $0.50 per million output tokens; o3 costs $2.00 and $8.00. Cost per solved task is known for o3 only.
Which has the bigger context window, GPT-6 Luna or o3?
GPT-6 Luna, with 1.05M tokens against 200K.
How many benchmarks is the GPT-6 Luna vs o3 comparison based on?
59 benchmarks have a result for both models as of October 22, 2026. GPT-6 Luna's coding index rests on 5 independent benchmarks and o3's on 0. Where only one model has a result, the page says so instead of naming a winner.