GPT-5 Nano vs Solar Pro 4
Updated October 21, 2026. 37 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-5 Nano for coding: it scores 34.8 on the Vibe Coding Index against 24.4 for Solar Pro 4.
Pick Solar Pro 4 when the context window is larger, 524K against 400K tokens, or when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.
- Shared results
- 37
- GPT-5 Nano only
- 48
- Solar Pro 4 only
- 8
- Like-for-like categories
- 7 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-5 Nano
GPT-5 Nano scores 34.8 against 24.4.
One benchmark behind each score
Intelligence
AA Intelligence Index
Solar Pro 4
Solar Pro 4 leads, 28.2 against 13.0.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only GPT-5 Nano has a GPQA Diamond result, 63.4%.
Directional only
Math
AIME
No call
Only GPT-5 Nano has a AIME result, 81.2%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5 Nano has a MMLU Pro result, 76.1%.
Directional only
Web design
Design Arena: websites
Solar Pro 4
Solar Pro 4 leads, 1176 against 1101.
Same board, both measured
Long documents
Listed context window
Solar Pro 4
Solar Pro 4 takes 524K tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5 Nano
GPT-5 Nano $0.0003, Solar Pro 4 $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5 Nano has the number, $0.109.
Directional only
At a glance
- Coding index
- GPT-5 Nano 34.8 from 1 benchmark, Solar Pro 4 24.4 from 1 benchmark.
- Widest category
- Reasoning, 17.2 points apart on average over 5 shared benchmarks.
- Widest single gap
- Design Arena: 3D: GPT-5 Nano 966 against Solar Pro 4 1178, 26.5 points apart on a 0 to 100 scale.
- Output price
- GPT-5 Nano $0.40 against Solar Pro 4 $0.60 per million output tokens, 1.5x apart.
- Context window
- GPT-5 Nano takes 400K 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-5 Nano | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 0 | 2 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 0 | 5 | ||
| Math | 0 | 2 | ||
| Knowledge | 0 | 4 | ||
| Web design | 0 | 6 | ||
| General | 1 | 16 | ||
| All shared boards | 1 | 36 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index02
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| SWE-bench Verified | 34.8% | Not measured | Only GPT-5 Nano measured |
| LMArena WebDev | Not measured | 1371 | Only Solar Pro 4 measured |
| AA Coding Index | Not measured | 52.7 | Only Solar Pro 4 measured |
| LiveCodeBench (Vals AI) | 70.2% | Not measured | Only GPT-5 Nano measured |
| LiveCodeBench (Artificial Analysis run) | 78.9% | Not measured | Only GPT-5 Nano measured |
| SciCode | Not measured | 48.0% | Only Solar Pro 4 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 17.4% | Not measured | Only GPT-5 Nano measured |
| Terminal-Bench | 21.8% | Not measured | Only GPT-5 Nano measured |
| WeirdML | 38.1% | Not measured | Only GPT-5 Nano measured |
| ALE-Bench | Not measured | 179.3 | Only Solar Pro 4 measured |
| LMArena Text: coding | 1351 | 1438 | Solar Pro 4 |
| LMArena Text: software and IT | 1345 | 1431 | Solar Pro 4 |
| LMArena WebDev: React | Not measured | 1363 | Only Solar Pro 4 measured |
| LMArena WebDev: HTML | Not measured | 1371 | Only Solar Pro 4 measured |
| Neither model has a result on the other 24 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 13.0 | 28.2 | Solar Pro 4 |
| Epoch Capabilities Index | 139.2 | Not measured | Only GPT-5 Nano measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1105 | Only Solar Pro 4 measured |
| τ²-Bench Telecom | 36.5% | Not measured | Only GPT-5 Nano measured |
| Neither model has a result on the other 37 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index05
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| GPQA Diamond | 63.4% | Not measured | Only GPT-5 Nano measured |
| MMMU Pro (Vals AI) | 70.9% | Not measured | Only GPT-5 Nano measured |
| GPQA Diamond (Artificial Analysis run) | 67.6% | 89.1% | Solar Pro 4 |
| Humanity's Last Exam (Artificial Analysis run) | 9.5% | 29.8% | Solar Pro 4 |
| GPQA Diamond (Epoch AI run) | 69.4% | Not measured | Only GPT-5 Nano measured |
| ARC-AGI | 20.7% | Not measured | Only GPT-5 Nano measured |
| ARC-AGI-2 | 2.6% | Not measured | Only GPT-5 Nano measured |
| Chess puzzles | 22.0% | Not measured | Only GPT-5 Nano measured |
| Mystery game puzzles | 9.0% | Not measured | Only GPT-5 Nano measured |
| VPCT | 37.2% | Not measured | Only GPT-5 Nano measured |
| LMArena Text: hard prompts | 1328 | 1400 | Solar Pro 4 |
| LMArena Text: expert | 1321 | 1428 | Solar Pro 4 |
| LMArena Text: hard prompts in English | 1338 | 1427 | Solar Pro 4 |
| LMArena Vision: diagrams | 1141 | Not measured | Only GPT-5 Nano measured |
| LMArena Vision: homework | 1157 | Not measured | Only GPT-5 Nano measured |
| Neither model has a result on the other 6 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| AIME | 81.2% | Not measured | Only GPT-5 Nano measured |
| MATH 500 (Vals AI) | 93.8% | Not measured | Only GPT-5 Nano measured |
| MGSM (Vals AI) | 89.3% | Not measured | Only GPT-5 Nano measured |
| AA Math Index | 83.7 | Not measured | Only GPT-5 Nano measured |
| AIME 2025 (Artificial Analysis run) | 83.7% | Not measured | Only GPT-5 Nano measured |
| OTIS Mock AIME | 81.1% | Not measured | Only GPT-5 Nano measured |
| FrontierMath, tiers 1 to 3 | 20.0% | Not measured | Only GPT-5 Nano measured |
| FrontierMath, tier 4 | 2.4% | Not measured | Only GPT-5 Nano measured |
| ProofBench | 12.0% | Not measured | Only GPT-5 Nano measured |
| MATH level 5 | 95.2% | Not measured | Only GPT-5 Nano measured |
| LMArena Text: math | 1317 | 1421 | Solar Pro 4 |
| LMArena Text: mathematical work | 1326 | 1427 | Solar Pro 4 |
| Neither model has a result on the other 1 board here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 76.1% | Not measured | Only GPT-5 Nano measured |
| LegalBench (Vals AI) | 50.1% | Not measured | Only GPT-5 Nano measured |
| CaseLaw (Vals AI) | 52.6% | Not measured | Only GPT-5 Nano measured |
| TaxEval (Vals AI) | 67.4% | Not measured | Only GPT-5 Nano measured |
| MortgageTax (Vals AI) | 53.6% | Not measured | Only GPT-5 Nano measured |
| MedQA (Vals AI) | 93.3% | Not measured | Only GPT-5 Nano measured |
| MedCode (Vals AI) | 30.4% | Not measured | Only GPT-5 Nano measured |
| MMLU Pro (Artificial Analysis run) | 78.0% | Not measured | Only GPT-5 Nano measured |
| SimpleQA Verified | 11.7% | Not measured | Only GPT-5 Nano measured |
| LMArena Text: science | 1318 | 1404 | Solar Pro 4 |
| LMArena Text: medicine and healthcare | 1335 | 1374 | Solar Pro 4 |
| LMArena Text: legal and government | 1298 | 1383 | Solar Pro 4 |
| LMArena Text: business and finance | 1311 | 1381 | Solar Pro 4 |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1101 | 1176 | Solar Pro 4 |
| Design Arena: UI components | 1066 | 1150 | Solar Pro 4 |
| Design Arena: game dev | 1045 | 1170 | Solar Pro 4 |
| Design Arena: data viz | 1056 | 1177 | Solar Pro 4 |
| Design Arena: 3D | 966 | 1178 | Solar Pro 4 |
| Design Arena: all code categories | 1084 | 1182 | Solar Pro 4 |
| Neither model has a result on the other 3 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index116
| Benchmark | GPT-5 Nano | Solar Pro 4 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 30.4% | Not measured | Only GPT-5 Nano measured |
| MedScribe (Vals AI) | 72.9% | Not measured | Only GPT-5 Nano measured |
| IFBench | 67.6% | Not measured | Only GPT-5 Nano measured |
| Long context reasoning (AA-LCR) | 45.0% | 70.7% | Solar Pro 4 |
| DTBench | 62.7% | Not measured | Only GPT-5 Nano measured |
| LMCA | 7.9% | Not measured | Only GPT-5 Nano measured |
| Fiction.LiveBench | 44.4% | Not measured | Only GPT-5 Nano measured |
| LMArena Text | 1320 | 1388 | Solar Pro 4 |
| LMArena Text: instruction following | 1306 | 1375 | Solar Pro 4 |
| LMArena Text: creative writing | 1249 | 1317 | Solar Pro 4 |
| LMArena Vision | 1159 | Not measured | Only GPT-5 Nano measured |
| LMArena Text: English | 1321 | 1414 | Solar Pro 4 |
| LMArena Text: non-English | 1313 | 1363 | Solar Pro 4 |
| LMArena Text: Chinese | 1356 | 1422 | Solar Pro 4 |
| LMArena Text: German | 1327 | 1358 | Solar Pro 4 |
| LMArena Text: Japanese | 1227 | 1320 | Solar Pro 4 |
| LMArena Text: Korean | 1269 | 1383 | Solar Pro 4 |
| LMArena Text: French | Not measured | 1400 | Only Solar Pro 4 measured |
| LMArena Text: Spanish | 1360 | 1409 | Solar Pro 4 |
| LMArena Text: Russian | 1296 | 1357 | Solar Pro 4 |
| LMArena Text: Polish | 1314 | 1304 | GPT-5 Nano |
| LMArena Text: multi-turn | 1311 | 1385 | Solar Pro 4 |
| LMArena Text: longer queries | 1312 | 1382 | Solar Pro 4 |
| LMArena Text: writing and language | 1283 | 1344 | Solar Pro 4 |
| LMArena Text: entertainment and media | 1268 | 1332 | Solar Pro 4 |
| LMArena Vision: English | 1170 | Not measured | Only GPT-5 Nano measured |
| LMArena Vision: Chinese | 1176 | Not measured | Only GPT-5 Nano measured |
| LMArena Vision: reading text | 1152 | Not measured | Only GPT-5 Nano measured |
| LMArena Vision: humor | 1110 | Not measured | Only GPT-5 Nano measured |
| Neither model has a result on the other 17 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5 Nano | 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-5 Nano costs less
Repository review
50K input + 3K output tokens
GPT-5 Nano costs less
Agent loop
200K input + 10K output tokens
GPT-5 Nano 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 Nano | Upstage Solar Pro 4 |
|---|---|---|
| Maker | OpenAI | Upstage |
| Weights | No public weights listed | No public weights listed |
| Released | August 7, 2025 | August 10, 2026 |
| Context window | 400K | 524K |
| Input $/Mtok | $0.05 | $0.15 |
| Output $/Mtok | $0.40 | $0.60 |
| Coding index | 34.8 | 24.4 |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | $0.109 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5 Nano better than Solar Pro 4 for coding?
Pick GPT-5 Nano for coding: it scores 34.8 on the Vibe Coding Index against 24.4 for Solar Pro 4. Pick Solar Pro 4 when the context window is larger, 524K against 400K tokens, or when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.
Which is cheaper, GPT-5 Nano or Solar Pro 4?
GPT-5 Nano costs $0.05 per million input tokens and $0.40 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for GPT-5 Nano only.
Which has the bigger context window, GPT-5 Nano or Solar Pro 4?
Solar Pro 4, with 524K tokens against 400K.
How many benchmarks is the GPT-5 Nano vs Solar Pro 4 comparison based on?
37 benchmarks have a result for both models as of October 21, 2026. GPT-5 Nano's coding index rests on 1 independent benchmark and Solar Pro 4's on 1. Where only one model has a result, the page says so instead of naming a winner.