GPT-6 Luna vs Solar Pro 4
Updated October 21, 2026. 43 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick GPT-6 Luna for coding: it scores 71.4 on the Vibe Coding Index against 24.4 for Solar Pro 4.
Pick Solar Pro 4 when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.
- Shared results
- 43
- GPT-6 Luna only
- 59
- Solar Pro 4 only
- 2
- Like-for-like categories
- 8 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
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, four public coding benchmarks
GPT-6 Luna
GPT-6 Luna scores 71.4 against 24.4.
2 and 1 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-6 Luna
GPT-6 Luna leads, 38.1 against 28.2.
Same board, both measured
Web design
Design Arena: websites
GPT-6 Luna
GPT-6 Luna leads, 1272 against 1176.
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 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-6 Luna
GPT-6 Luna $0.0003, Solar Pro 4 $0.0004 per turn.
List prices
At a glance
- Coding index
- GPT-6 Luna 71.4 from 2 benchmarks, Solar Pro 4 24.4 from 1 benchmark.
- Widest category
- Coding, 22.4 points apart on average over 7 shared benchmarks.
- Widest single gap
- ALE-Bench: GPT-6 Luna 1576.9 against Solar Pro 4 179.3, 46.6 points apart on a 0 to 100 scale.
- Output price
- GPT-6 Luna $0.50 against Solar Pro 4 $0.60 per million output tokens, 1.2x apart.
- Context window
- GPT-6 Luna takes 1.05M tokens, Solar Pro 4 524K.
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 | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 5 | 2 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 3 | 1 | ||
| Math | 0 | 2 | ||
| Knowledge | 2 | 2 | ||
| Web design | 6 | 0 | ||
| General | 15 | 3 | ||
| All shared boards | 33 | 10 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index52
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| LiveBench coding | 84.5% | Not measured | Only GPT-6 Luna measured |
| LMArena WebDev | 1578 | 1371 | GPT-6 Luna |
| AA Coding Index | Not measured | 52.7 | Only Solar Pro 4 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 |
| SciCode | 54.6% | 48.0% | GPT-6 Luna |
| FrontierCode | 42.4% | Not measured | Only GPT-6 Luna measured |
| ALE-Bench | 1576.9 | 179.3 | GPT-6 Luna |
| LMArena Text: coding | 1437 | 1438 | Solar Pro 4 |
| LMArena Text: software and IT | 1423 | 1431 | Solar Pro 4 |
| LMArena WebDev: React | 1573 | 1363 | GPT-6 Luna |
| LMArena WebDev: HTML | 1595 | 1371 | GPT-6 Luna |
| LMArena WebDev: from an image | 1571 | Not measured | Only GPT-6 Luna measured |
| Neither model has a result on the other 19 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.1 | 28.2 | GPT-6 Luna |
| Epoch Capabilities Index | 156.8 | Not measured | Only GPT-6 Luna measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1189 | 1105 | GPT-6 Luna |
| Design Arena: agents building full-stack apps | 1158 | Not measured | Only GPT-6 Luna measured |
| Design Arena: agents building mobile apps | 1133 | 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 |
| APEX-Agents | 44.3% | Not measured | Only GPT-6 Luna measured |
| SpireClimb | 0.0% | Not measured | Only GPT-6 Luna measured |
| Neither model has a result on the other 22 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index31
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| LiveBench reasoning | 81.8% | Not measured | Only GPT-6 Luna measured |
| MysteryMechanism (Vals AI) | 19.4% | Not measured | Only GPT-6 Luna measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 89.1% | Only Solar Pro 4 measured |
| Humanity's Last Exam (Artificial Analysis run) | 38.5% | 29.8% | GPT-6 Luna |
| GPQA Diamond (Epoch AI run) | 90.5% | Not measured | Only GPT-6 Luna measured |
| ARC-AGI | 86.7% | Not measured | Only GPT-6 Luna measured |
| ARC-AGI-2 | 59.3% | Not measured | Only GPT-6 Luna measured |
| Chess puzzles | 36.0% | Not measured | Only GPT-6 Luna measured |
| Mystery game puzzles | 7.0% | Not measured | Only GPT-6 Luna measured |
| LMArena Text: hard prompts | 1410 | 1400 | GPT-6 Luna |
| LMArena Text: expert | 1442 | 1428 | GPT-6 Luna |
| LMArena Text: hard prompts in English | 1410 | 1427 | Solar Pro 4 |
| LMArena Vision: diagrams | 1245 | Not measured | Only GPT-6 Luna measured |
| LMArena Vision: homework | 1261 | Not measured | Only GPT-6 Luna measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 98.9% | Not measured | Only GPT-6 Luna measured |
| FrontierMath, tiers 1 to 3 | 78.9% | Not measured | Only GPT-6 Luna measured |
| FrontierMath, tier 4 | 56.1% | Not measured | Only GPT-6 Luna measured |
| ProofBench | 64.0% | Not measured | Only GPT-6 Luna measured |
| LMArena Text: math | 1409 | 1421 | Solar Pro 4 |
| LMArena Text: mathematical work | 1427 | 1427 | Solar Pro 4 |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index22
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| MedCode (Vals AI) | 44.7% | Not measured | Only GPT-6 Luna measured |
| SimpleQA Verified | 41.4% | Not measured | Only GPT-6 Luna measured |
| LMArena Text: science | 1386 | 1404 | Solar Pro 4 |
| LMArena Text: medicine and healthcare | 1352 | 1374 | Solar Pro 4 |
| LMArena Text: legal and government | 1400 | 1383 | GPT-6 Luna |
| LMArena Text: business and finance | 1388 | 1381 | GPT-6 Luna |
| Neither model has a result on the other 11 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | GPT-6 Luna | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1272 | 1176 | GPT-6 Luna |
| Design Arena: UI components | 1297 | 1150 | GPT-6 Luna |
| Design Arena: game dev | 1259 | 1170 | GPT-6 Luna |
| Design Arena: data viz | 1215 | 1177 | GPT-6 Luna |
| Design Arena: 3D | 1217 | 1178 | GPT-6 Luna |
| Design Arena: all code categories | 1271 | 1182 | GPT-6 Luna |
| Design Arena: SVG | 1253 | Not measured | Only GPT-6 Luna measured |
| Design Arena: ASCII art | 1156 | 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 index153
| Benchmark | GPT-6 Luna | Solar Pro 4 | 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% | Not measured | Only GPT-6 Luna measured |
| MedScribe (Vals AI) | 83.7% | Not measured | Only GPT-6 Luna measured |
| Long context reasoning (AA-LCR) | 83.3% | 70.7% | GPT-6 Luna |
| DTBench | 90.1% | Not measured | Only GPT-6 Luna measured |
| LMCA | 44.5% | Not measured | Only GPT-6 Luna measured |
| Furniture assembly | 44.2% | Not measured | Only GPT-6 Luna measured |
| LMArena Text | 1389 | 1388 | GPT-6 Luna |
| LMArena Text: instruction following | 1408 | 1375 | GPT-6 Luna |
| LMArena Text: creative writing | 1363 | 1317 | GPT-6 Luna |
| LMArena Vision | 1216 | Not measured | Only GPT-6 Luna measured |
| LMArena Text: English | 1393 | 1414 | Solar Pro 4 |
| LMArena Text: non-English | 1381 | 1363 | GPT-6 Luna |
| LMArena Text: Chinese | 1427 | 1422 | GPT-6 Luna |
| LMArena Text: German | 1376 | 1358 | GPT-6 Luna |
| LMArena Text: Japanese | 1369 | 1320 | GPT-6 Luna |
| LMArena Text: Korean | 1359 | 1383 | Solar Pro 4 |
| LMArena Text: French | 1408 | 1400 | GPT-6 Luna |
| LMArena Text: Spanish | 1391 | 1409 | Solar Pro 4 |
| LMArena Text: Russian | 1392 | 1357 | GPT-6 Luna |
| LMArena Text: Polish | 1383 | 1304 | GPT-6 Luna |
| LMArena Text: multi-turn | 1392 | 1385 | GPT-6 Luna |
| LMArena Text: longer queries | 1408 | 1382 | GPT-6 Luna |
| LMArena Text: writing and language | 1384 | 1344 | GPT-6 Luna |
| LMArena Text: entertainment and media | 1364 | 1332 | GPT-6 Luna |
| LMArena Vision: English | 1204 | Not measured | Only GPT-6 Luna measured |
| LMArena Vision: Chinese | 1266 | Not measured | Only GPT-6 Luna measured |
| LMArena Vision: reading text | 1225 | Not measured | Only GPT-6 Luna measured |
| LMArena Vision: creative writing | 1205 | Not measured | Only GPT-6 Luna measured |
| Neither model has a result on the other 15 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-6 Luna | Solar Pro 4 | 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 | Upstage Solar Pro 4 |
|---|---|---|
| Maker | OpenAI | Upstage |
| Weights | No public weights listed | No public weights listed |
| Released | September 22, 2026 | August 10, 2026 |
| Context window | 1.05M | 524K |
| Input $/Mtok | $0.10 | $0.15 |
| Output $/Mtok | $0.50 | $0.60 |
| Coding index | 71.4 | 24.4 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-6 Luna better than Solar Pro 4 for coding?
Pick GPT-6 Luna for coding: it scores 71.4 on the Vibe Coding Index against 24.4 for Solar Pro 4. Pick Solar Pro 4 when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.
Which is cheaper, GPT-6 Luna or Solar Pro 4?
GPT-6 Luna costs $0.10 per million input tokens and $0.50 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-6 Luna or Solar Pro 4?
GPT-6 Luna, with 1.05M tokens against 524K.
How many benchmarks is the GPT-6 Luna vs Solar Pro 4 comparison based on?
43 benchmarks have a result for both models as of October 21, 2026. GPT-6 Luna's coding index rests on 2 independent benchmarks and Solar Pro 4's on 1. Where only one model has a result, the page says so instead of naming a winner.