GPT-5 Mini vs GPT-6 Luna
GPT-6 Luna leads GPT-5 Mini on coding, 57.3 to 34.2 on the Vibe Coding Index, and GPT-6 Luna costs 4.0x less per output token ($0.50 vs $2.00 per million). Updated October 22, 2026; 65 benchmarks have a result for both.
GPT-5 Mini or GPT-6 Luna: which to pick
Pick GPT-6 Luna for coding: it scores 57.3 on the Vibe Coding Index against 34.2 for GPT-5 Mini.
Pick GPT-5 Mini for work measured by Mystery game puzzles or LMArena Text: medicine and healthcare, where it leads.
- Shared results
- 65
- GPT-5 Mini only
- 36
- GPT-6 Luna only
- 38
- 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
GPT-6 Luna
GPT-6 Luna scores 57.3 against 34.2.
2 and 5 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-6 Luna
GPT-6 Luna leads, 38.1 against 20.6.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only GPT-5 Mini has a GPQA Diamond result, 80.3%.
Directional only
Math
AIME
No call
Only GPT-5 Mini has a AIME result, 91.5%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5 Mini has a MMLU Pro result, 82.2%.
Directional only
Web design
Design Arena: websites
GPT-6 Luna
GPT-6 Luna leads, 1271 against 1125.
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 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-6 Luna
GPT-5 Mini $0.0013, GPT-6 Luna $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5 Mini has the number, $0.08.
Directional only
At a glance
- Coding index
- GPT-5 Mini 34.2 from 2 benchmarks, GPT-6 Luna 57.3 from 5 benchmarks.
- Widest category
- Math, 26.1 points apart on average over 6 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): GPT-5 Mini 14.2% against GPT-6 Luna 81.7%, 67.5 points apart on a 0 to 100 scale.
- Output price
- GPT-5 Mini $2.00 against GPT-6 Luna $0.50 per million output tokens, 4.0x apart.
- Context window
- GPT-5 Mini takes 400K tokens, GPT-6 Luna 1.05M.
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-5 Mini | Bars | GPT-6 Luna | Ties |
|---|---|---|---|---|
| Coding | 0 | 4 | ||
| Intelligence | 0 | 2 | ||
| Reasoning | 1 | 10 | ||
| Math | 0 | 6 | ||
| Knowledge | 1 | 6 | ||
| Web design | 0 | 8 | ||
| General | 1 | 26 | ||
| All shared boards | 3 | 62 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index04
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| SWE-bench Verified | 59.8% | Not measured | Only GPT-5 Mini measured |
| SWE-bench Multilingual | 39.7% | Not measured | Only GPT-5 Mini measured |
| LiveBench coding | Not measured | 84.5% | Only GPT-6 Luna measured |
| LMArena WebDev | Not measured | 1578 | Only GPT-6 Luna measured |
| LiveCodeBench (Vals AI) | 86.6% | Not measured | Only GPT-5 Mini measured |
| SWE-bench Verified (Vals AI) | 60.8% | Not measured | Only GPT-5 Mini measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 13.6% | Only GPT-6 Luna measured |
| Vibe Code Bench (Vals AI) | 14.2% | 81.7% | GPT-6 Luna |
| Code migration (Vals AI) | Not measured | 42.5% | Only GPT-6 Luna measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only GPT-6 Luna measured |
| IOI (Vals AI) | Not measured | 55.6% | Only GPT-6 Luna measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 73.0% | Only GPT-6 Luna measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 37.5% | Only GPT-6 Luna measured |
| CyberBench (Vals AI) | Not measured | 76.3% | Only GPT-6 Luna measured |
| LiveCodeBench (Artificial Analysis run) | 83.8% | Not measured | Only GPT-5 Mini measured |
| SciCode | 39.0% | 54.6% | GPT-6 Luna |
| Terminal-Bench Hard (Artificial Analysis run) | 33.3% | Not measured | Only GPT-5 Mini measured |
| Terminal-Bench | 34.8% | Not measured | Only GPT-5 Mini measured |
| FrontierCode | Not measured | 42.4% | Only GPT-6 Luna measured |
| WeirdML | 52.7% | Not measured | Only GPT-5 Mini measured |
| ALE-Bench | Not measured | 1576.9 | Only GPT-6 Luna measured |
| LMArena Text: coding | 1406 | 1437 | GPT-6 Luna |
| LMArena Text: software and IT | 1394 | 1423 | GPT-6 Luna |
| LMArena WebDev: React | Not measured | 1573 | Only GPT-6 Luna measured |
| LMArena WebDev: HTML | Not measured | 1595 | Only GPT-6 Luna measured |
| LMArena WebDev: from an image | Not measured | 1571 | Only GPT-6 Luna measured |
| Neither model has a result on the other 13 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.6 | 38.1 | GPT-6 Luna |
| Epoch Capabilities Index | 145.3 | 156.8 | GPT-6 Luna |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index20 boards, none shared
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1191 | Only GPT-6 Luna measured |
| Design Arena: agents building full-stack apps | Not measured | 1158 | Only GPT-6 Luna measured |
| Design Arena: agents building mobile apps | Not measured | 1134 | Only GPT-6 Luna measured |
| LiveBench research | Not measured | 43.5% | Only GPT-6 Luna measured |
| LiveBench browser | Not measured | 72.0% | Only GPT-6 Luna measured |
| LiveBench long agentic | Not measured | 48.1% | Only GPT-6 Luna measured |
| SREBench (Vals AI) | Not measured | 2.7% | Only GPT-6 Luna measured |
| Finance Agent (Vals AI) | Not measured | 49.9% | Only GPT-6 Luna measured |
| Tax Agent Bench (Vals AI) | Not measured | 19.9% | Only GPT-6 Luna measured |
| Legal Research Bench (Vals AI) | Not measured | 30.3% | Only GPT-6 Luna measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 4.2% | Only GPT-6 Luna measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 68.5% | Only GPT-6 Luna measured |
| BioMysteryBench (Vals AI) | Not measured | 61.5% | Only GPT-6 Luna measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 4.3% | Only GPT-6 Luna measured |
| Vals Science Index | Not measured | 28.4% | Only GPT-6 Luna measured |
| τ²-Bench Telecom | 71.1% | Not measured | Only GPT-5 Mini measured |
| APEX-Agents | Not measured | 44.3% | Only GPT-6 Luna measured |
| SpireClimb | Not measured | 0.0% | Only GPT-6 Luna measured |
| Vending-Bench 2 | -$31 | Not measured | Only GPT-5 Mini measured |
| Berkeley Function Calling Leaderboard (BFCL) | 55.5% | Not measured | Only GPT-5 Mini measured |
| Neither model has a result on the other 21 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index110
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| GPQA Diamond | 80.3% | Not measured | Only GPT-5 Mini measured |
| LiveBench reasoning | Not measured | 81.8% | Only GPT-6 Luna measured |
| MysteryMechanism (Vals AI) | Not measured | 19.4% | Only GPT-6 Luna measured |
| MMMU Pro (Vals AI) | 78.9% | Not measured | Only GPT-5 Mini measured |
| GPQA Diamond (Artificial Analysis run) | 82.8% | Not measured | Only GPT-5 Mini measured |
| Humanity's Last Exam (Artificial Analysis run) | 21.5% | 38.5% | GPT-6 Luna |
| GPQA Diamond (Epoch AI run) | 75.0% | 90.5% | GPT-6 Luna |
| ARC-AGI | 54.3% | 86.7% | GPT-6 Luna |
| ARC-AGI-2 | 4.4% | 59.3% | GPT-6 Luna |
| Chess puzzles | 24.0% | 36.0% | GPT-6 Luna |
| Mystery game puzzles | 10.0% | 7.0% | GPT-5 Mini |
| VPCT | 40.2% | Not measured | Only GPT-5 Mini measured |
| LMArena Text: hard prompts | 1380 | 1410 | GPT-6 Luna |
| LMArena Text: expert | 1379 | 1442 | GPT-6 Luna |
| LMArena Text: hard prompts in English | 1383 | 1410 | GPT-6 Luna |
| LMArena Vision: diagrams | 1202 | 1245 | GPT-6 Luna |
| LMArena Vision: homework | 1210 | 1261 | GPT-6 Luna |
| Kagi LLM Benchmark | 70.3% | Not measured | Only GPT-5 Mini measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| AIME | 91.5% | Not measured | Only GPT-5 Mini measured |
| MATH 500 (Vals AI) | 94.8% | Not measured | Only GPT-5 Mini measured |
| MGSM (Vals AI) | 92.6% | Not measured | Only GPT-5 Mini measured |
| AA Math Index | 90.7 | Not measured | Only GPT-5 Mini measured |
| AIME 2025 (Artificial Analysis run) | 90.7% | Not measured | Only GPT-5 Mini measured |
| OTIS Mock AIME | 86.7% | 98.9% | GPT-6 Luna |
| FrontierMath, tiers 1 to 3 | 46.7% | 78.9% | GPT-6 Luna |
| FrontierMath, tier 4 | 12.2% | 56.1% | GPT-6 Luna |
| ProofBench | 9.0% | 64.0% | GPT-6 Luna |
| MATH level 5 | 97.8% | Not measured | Only GPT-5 Mini measured |
| LMArena Text: math | 1378 | 1409 | GPT-6 Luna |
| LMArena Text: mathematical work | 1380 | 1427 | 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-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| MMLU Pro | 82.2% | Not measured | Only GPT-5 Mini measured |
| LegalBench (Vals AI) | 81.8% | Not measured | Only GPT-5 Mini measured |
| CaseLaw (Vals AI) | 68.5% | Not measured | Only GPT-5 Mini measured |
| CorpFin (Vals AI) | 60.2% | Not measured | Only GPT-5 Mini measured |
| TaxEval (Vals AI) | 75.2% | Not measured | Only GPT-5 Mini measured |
| MortgageTax (Vals AI) | 66.9% | Not measured | Only GPT-5 Mini measured |
| MedQA (Vals AI) | 96.1% | Not measured | Only GPT-5 Mini measured |
| MedCode (Vals AI) | 43.0% | 44.7% | GPT-6 Luna |
| MMLU Pro (Artificial Analysis run) | 83.7% | Not measured | Only GPT-5 Mini measured |
| SimpleQA Verified | 21.6% | 41.4% | GPT-6 Luna |
| LMArena Text: science | 1371 | 1386 | GPT-6 Luna |
| LMArena Text: medicine and healthcare | 1380 | 1352 | GPT-5 Mini |
| LMArena Text: legal and government | 1375 | 1400 | GPT-6 Luna |
| LMArena Text: business and finance | 1358 | 1388 | GPT-6 Luna |
| FACTS Benchmark Suite | 38.6% | 63.3% | 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 index08
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| Design Arena: websites | 1125 | 1271 | GPT-6 Luna |
| Design Arena: UI components | 1103 | 1295 | GPT-6 Luna |
| Design Arena: game dev | 1129 | 1257 | GPT-6 Luna |
| Design Arena: data viz | 1131 | 1216 | GPT-6 Luna |
| Design Arena: 3D | 1036 | 1218 | GPT-6 Luna |
| Design Arena: all code categories | 1114 | 1270 | GPT-6 Luna |
| Design Arena: SVG | 1091 | 1252 | GPT-6 Luna |
| Design Arena: ASCII art | 1125 | 1153 | GPT-6 Luna |
| LiveBench design | Not measured | 82.5% | Only GPT-6 Luna measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index126
| Benchmark | GPT-5 Mini | GPT-6 Luna | Leader |
|---|---|---|---|
| Vals Index | Not measured | 52.3% | Only GPT-6 Luna measured |
| LiveBench data analysis | Not measured | 73.4% | Only GPT-6 Luna measured |
| Public Benefits Bench (Vals AI) | Not measured | 57.6% | Only GPT-6 Luna measured |
| SAGE (Vals AI) | 43.0% | 48.1% | GPT-6 Luna |
| MedScribe (Vals AI) | 80.6% | 83.7% | GPT-6 Luna |
| IFBench | 75.4% | Not measured | Only GPT-5 Mini measured |
| Long context reasoning (AA-LCR) | 72.3% | 83.3% | GPT-6 Luna |
| DTBench | 80.5% | 90.1% | GPT-6 Luna |
| LMCA | 34.2% | 44.5% | GPT-6 Luna |
| Fiction.LiveBench | 69.4% | Not measured | Only GPT-5 Mini measured |
| Creative writing (Lech Mazur) | 83.1% | Not measured | Only GPT-5 Mini measured |
| Furniture assembly | Not measured | 44.2% | Only GPT-6 Luna measured |
| LMArena Text | 1373 | 1389 | GPT-6 Luna |
| LMArena Text: instruction following | 1357 | 1408 | GPT-6 Luna |
| LMArena Text: creative writing | 1325 | 1363 | GPT-6 Luna |
| LMArena Vision | 1202 | 1216 | GPT-6 Luna |
| LMArena Text: English | 1379 | 1393 | GPT-6 Luna |
| LMArena Text: non-English | 1363 | 1381 | GPT-6 Luna |
| LMArena Text: Chinese | 1386 | 1427 | GPT-6 Luna |
| LMArena Text: German | 1366 | 1376 | GPT-6 Luna |
| LMArena Text: Japanese | 1341 | 1369 | GPT-6 Luna |
| LMArena Text: Korean | 1308 | 1359 | GPT-6 Luna |
| LMArena Text: French | 1386 | 1408 | GPT-6 Luna |
| LMArena Text: Spanish | 1354 | 1391 | GPT-6 Luna |
| LMArena Text: Russian | 1362 | 1392 | GPT-6 Luna |
| LMArena Text: Polish | 1378 | 1383 | GPT-6 Luna |
| LMArena Text: multi-turn | 1363 | 1392 | GPT-6 Luna |
| LMArena Text: longer queries | 1355 | 1408 | GPT-6 Luna |
| LMArena Text: writing and language | 1344 | 1384 | GPT-6 Luna |
| LMArena Text: entertainment and media | 1340 | 1364 | GPT-6 Luna |
| LMArena Vision: English | 1216 | 1204 | GPT-5 Mini |
| LMArena Vision: Chinese | 1214 | 1266 | GPT-6 Luna |
| LMArena Vision: reading text | 1199 | 1225 | GPT-6 Luna |
| LMArena Vision: humor | 1205 | Not measured | Only GPT-5 Mini measured |
| LMArena Vision: captioning | 1217 | Not measured | Only GPT-5 Mini measured |
| LMArena Vision: recognizing things | 1226 | Not measured | Only GPT-5 Mini measured |
| LMArena Vision: creative writing | 1181 | 1205 | GPT-6 Luna |
| Neither model has a result on the other 9 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5 Mini | GPT-6 Luna | 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-5 Mini | OpenAI GPT-6 Luna |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | August 7, 2025 | September 22, 2026 |
| Context window | 400K | 1.05M |
| Input $/Mtok | $0.25 | $0.10 |
| Output $/Mtok | $2.00 | $0.50 |
| Coding index | 34.2 | 57.3 |
| Independent measurements behind it | 2 | 5 |
| Cost per solved task | $0.08 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5 Mini better than GPT-6 Luna for coding?
Pick GPT-6 Luna for coding: it scores 57.3 on the Vibe Coding Index against 34.2 for GPT-5 Mini. Pick GPT-5 Mini for work measured by Mystery game puzzles or LMArena Text: medicine and healthcare, where it leads.
Which is cheaper, GPT-5 Mini or GPT-6 Luna?
GPT-5 Mini costs $0.25 per million input tokens and $2.00 per million output tokens; GPT-6 Luna costs $0.10 and $0.50. Cost per solved task is known for GPT-5 Mini only.
Which has the bigger context window, GPT-5 Mini or GPT-6 Luna?
GPT-6 Luna, with 1.05M tokens against 400K.
How many benchmarks is the GPT-5 Mini vs GPT-6 Luna comparison based on?
65 benchmarks have a result for both models as of October 22, 2026. GPT-5 Mini's coding index rests on 2 independent benchmarks and GPT-6 Luna's on 5. Where only one model has a result, the page says so instead of naming a winner.