GPT-5.1 vs Solar Pro 4
Updated October 21, 2026. 42 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-5.1 for coding: it scores 53.3 on the Vibe Coding Index against 24.4 for Solar Pro 4.
Pick Solar Pro 4 when output tokens cost 16.7x less, or when the context window is larger, 524K against 400K tokens.
- Shared results
- 42
- GPT-5.1 only
- 58
- Solar Pro 4 only
- 3
- 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-5.1
GPT-5.1 scores 53.3 against 24.4.
2 and 1 benchmarks behind the scores
Intelligence
AA Intelligence Index
Solar Pro 4
Solar Pro 4 leads, 28.2 against 24.7.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only GPT-5.1 has a GPQA Diamond result, 86.6%.
Directional only
Math
AIME
No call
Only GPT-5.1 has a AIME result, 93.3%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5.1 has a MMLU Pro result, 86.4%.
Directional only
Web design
Design Arena: websites
GPT-5.1
GPT-5.1 leads, 1187 against 1176.
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
Solar Pro 4
GPT-5.1 $0.0063, Solar Pro 4 $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5.1 has the number, $1.02.
Directional only
At a glance
- Coding index
- GPT-5.1 53.3 from 2 benchmarks, Solar Pro 4 24.4 from 1 benchmark.
- Widest category
- General, 11.9 points apart on average over 18 shared benchmarks.
- Widest single gap
- LMArena Text: Polish: GPT-5.1 1440 against Solar Pro 4 1304, 22.6 points apart on a 0 to 100 scale.
- Output price
- GPT-5.1 $10.00 against Solar Pro 4 $0.60 per million output tokens, 16.7x apart.
- Context window
- GPT-5.1 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-5.1 | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 4 | 2 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 3 | 2 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| Web design | 4 | 2 | ||
| General | 18 | 0 | ||
| All shared boards | 35 | 7 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index42
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| SWE-bench Verified | 66.0% | Not measured | Only GPT-5.1 measured |
| LMArena WebDev | 1396 | 1371 | GPT-5.1 |
| AA Coding Index | 49.4 | 52.7 | Solar Pro 4 |
| LiveCodeBench (Vals AI) | 86.5% | Not measured | Only GPT-5.1 measured |
| SWE-bench Verified (Vals AI) | 69.8% | Not measured | Only GPT-5.1 measured |
| Vibe Code Bench (Vals AI) | 24.6% | Not measured | Only GPT-5.1 measured |
| LiveCodeBench (Artificial Analysis run) | 86.8% | Not measured | Only GPT-5.1 measured |
| SciCode | Not measured | 48.0% | Only Solar Pro 4 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 45.5% | Not measured | Only GPT-5.1 measured |
| Terminal-Bench | 47.6% | Not measured | Only GPT-5.1 measured |
| GSO-Bench | 13.7% | Not measured | Only GPT-5.1 measured |
| WeirdML | 60.8% | Not measured | Only GPT-5.1 measured |
| ALE-Bench | Not measured | 179.3 | Only Solar Pro 4 measured |
| LMArena Text: coding | 1453 | 1438 | GPT-5.1 |
| LMArena Text: software and IT | 1454 | 1431 | GPT-5.1 |
| LMArena WebDev: React | 1307 | 1363 | Solar Pro 4 |
| LMArena WebDev: HTML | 1405 | 1371 | GPT-5.1 |
| LMArena WebDev: from an image | 1421 | Not measured | Only GPT-5.1 measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 24.7 | 28.2 | Solar Pro 4 |
| Epoch Capabilities Index | 149.8 | Not measured | Only GPT-5.1 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1105 | Only Solar Pro 4 measured |
| τ²-Bench Telecom | 81.9% | Not measured | Only GPT-5.1 measured |
| DeepResearch Bench | 42.8% | Not measured | Only GPT-5.1 measured |
| Vending-Bench 2 | $1,473 | Not measured | Only GPT-5.1 measured |
| Neither model has a result on the other 35 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index32
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| GPQA Diamond | 86.6% | Not measured | Only GPT-5.1 measured |
| MMMU Pro (Vals AI) | 83.2% | Not measured | Only GPT-5.1 measured |
| GPQA Diamond (Artificial Analysis run) | 87.3% | 89.1% | Solar Pro 4 |
| Humanity's Last Exam (Artificial Analysis run) | 28.5% | 29.8% | Solar Pro 4 |
| GPQA Diamond (Epoch AI run) | 87.6% | Not measured | Only GPT-5.1 measured |
| ARC-AGI | 72.8% | Not measured | Only GPT-5.1 measured |
| ARC-AGI-2 | 17.6% | Not measured | Only GPT-5.1 measured |
| SimpleBench | 53.2% | Not measured | Only GPT-5.1 measured |
| Chess puzzles | 42.0% | Not measured | Only GPT-5.1 measured |
| Mystery game puzzles | 19.0% | Not measured | Only GPT-5.1 measured |
| VPCT | 58.7% | Not measured | Only GPT-5.1 measured |
| LMArena Text: hard prompts | 1457 | 1400 | GPT-5.1 |
| LMArena Text: expert | 1470 | 1428 | GPT-5.1 |
| LMArena Text: hard prompts in English | 1462 | 1427 | GPT-5.1 |
| LMArena Vision: diagrams | 1264 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: homework | 1272 | Not measured | Only GPT-5.1 measured |
| Neither model has a result on the other 5 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| AIME | 93.3% | Not measured | Only GPT-5.1 measured |
| MGSM (Vals AI) | 93.0% | Not measured | Only GPT-5.1 measured |
| AA Math Index | 94.0 | Not measured | Only GPT-5.1 measured |
| AIME 2025 (Artificial Analysis run) | 94.0% | Not measured | Only GPT-5.1 measured |
| OTIS Mock AIME | 88.6% | Not measured | Only GPT-5.1 measured |
| LMArena Text: math | 1446 | 1421 | GPT-5.1 |
| LMArena Text: mathematical work | 1449 | 1427 | GPT-5.1 |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 86.4% | Not measured | Only GPT-5.1 measured |
| LegalBench (Vals AI) | 85.7% | Not measured | Only GPT-5.1 measured |
| CaseLaw (Vals AI) | 73.4% | Not measured | Only GPT-5.1 measured |
| CorpFin (Vals AI) | 63.8% | Not measured | Only GPT-5.1 measured |
| TaxEval (Vals AI) | 74.9% | Not measured | Only GPT-5.1 measured |
| MortgageTax (Vals AI) | 61.4% | Not measured | Only GPT-5.1 measured |
| MedQA (Vals AI) | 96.4% | Not measured | Only GPT-5.1 measured |
| MedCode (Vals AI) | 52.7% | Not measured | Only GPT-5.1 measured |
| MMLU Pro (Artificial Analysis run) | 87.0% | Not measured | Only GPT-5.1 measured |
| SimpleQA Verified | 48.0% | Not measured | Only GPT-5.1 measured |
| LMArena Text: science | 1459 | 1404 | GPT-5.1 |
| LMArena Text: medicine and healthcare | 1456 | 1374 | GPT-5.1 |
| LMArena Text: legal and government | 1459 | 1383 | GPT-5.1 |
| LMArena Text: business and finance | 1431 | 1381 | GPT-5.1 |
| Neither model has a result on the other 3 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index42
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1187 | 1176 | GPT-5.1 |
| Design Arena: UI components | 1166 | 1150 | GPT-5.1 |
| Design Arena: game dev | 1179 | 1170 | GPT-5.1 |
| Design Arena: data viz | 1204 | 1177 | GPT-5.1 |
| Design Arena: 3D | 1061 | 1178 | Solar Pro 4 |
| Design Arena: all code categories | 1171 | 1182 | Solar Pro 4 |
| Design Arena: SVG | 1149 | Not measured | Only GPT-5.1 measured |
| Design Arena: ASCII art | 1118 | Not measured | Only GPT-5.1 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index180
| Benchmark | GPT-5.1 | Solar Pro 4 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 43.2% | Not measured | Only GPT-5.1 measured |
| MedScribe (Vals AI) | 88.1% | Not measured | Only GPT-5.1 measured |
| IFBench | 72.9% | Not measured | Only GPT-5.1 measured |
| Long context reasoning (AA-LCR) | 80.0% | 70.7% | GPT-5.1 |
| DTBench | 90.1% | Not measured | Only GPT-5.1 measured |
| LMCA | 43.9% | Not measured | Only GPT-5.1 measured |
| CL-bench | 23.7% | Not measured | Only GPT-5.1 measured |
| CL-bench Life | 17.3% | Not measured | Only GPT-5.1 measured |
| LMArena Text | 1443 | 1388 | GPT-5.1 |
| LMArena Text: instruction following | 1443 | 1375 | GPT-5.1 |
| LMArena Text: creative writing | 1427 | 1317 | GPT-5.1 |
| LMArena Vision | 1250 | Not measured | Only GPT-5.1 measured |
| LMArena Text: English | 1451 | 1414 | GPT-5.1 |
| LMArena Text: non-English | 1431 | 1363 | GPT-5.1 |
| LMArena Text: Chinese | 1495 | 1422 | GPT-5.1 |
| LMArena Text: German | 1438 | 1358 | GPT-5.1 |
| LMArena Text: Japanese | 1453 | 1320 | GPT-5.1 |
| LMArena Text: Korean | 1401 | 1383 | GPT-5.1 |
| LMArena Text: French | 1450 | 1400 | GPT-5.1 |
| LMArena Text: Spanish | 1433 | 1409 | GPT-5.1 |
| LMArena Text: Russian | 1435 | 1357 | GPT-5.1 |
| LMArena Text: Polish | 1440 | 1304 | GPT-5.1 |
| LMArena Text: multi-turn | 1450 | 1385 | GPT-5.1 |
| LMArena Text: longer queries | 1448 | 1382 | GPT-5.1 |
| LMArena Text: writing and language | 1428 | 1344 | GPT-5.1 |
| LMArena Text: entertainment and media | 1415 | 1332 | GPT-5.1 |
| LMArena Vision: English | 1252 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: Chinese | 1270 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: reading text | 1255 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: humor | 1263 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: captioning | 1252 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: recognizing things | 1232 | Not measured | Only GPT-5.1 measured |
| LMArena Vision: creative writing | 1266 | Not measured | Only GPT-5.1 measured |
| LMArena Document | 1403 | Not measured | Only GPT-5.1 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
| Benchmark | GPT-5.1 | 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
Solar Pro 4 costs less
Repository review
50K input + 3K output tokens
Solar Pro 4 costs less
Agent loop
200K input + 10K output tokens
Solar Pro 4 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-5.1 | Upstage Solar Pro 4 |
|---|---|---|
| Maker | OpenAI | Upstage |
| Weights | No public weights listed | No public weights listed |
| Released | November 13, 2025 | August 10, 2026 |
| Context window | 400K | 524K |
| Input $/Mtok | $1.25 | $0.15 |
| Output $/Mtok | $10.00 | $0.60 |
| Coding index | 53.3 | 24.4 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | $1.02 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.1 better than Solar Pro 4 for coding?
Pick GPT-5.1 for coding: it scores 53.3 on the Vibe Coding Index against 24.4 for Solar Pro 4. Pick Solar Pro 4 when output tokens cost 16.7x less, or when the context window is larger, 524K against 400K tokens.
Which is cheaper, GPT-5.1 or Solar Pro 4?
GPT-5.1 costs $1.25 per million input tokens and $10.00 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for GPT-5.1 only.
Which has the bigger context window, GPT-5.1 or Solar Pro 4?
Solar Pro 4, with 524K tokens against 400K.
How many benchmarks is the GPT-5.1 vs Solar Pro 4 comparison based on?
42 benchmarks have a result for both models as of October 21, 2026. GPT-5.1'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.