Mistral Medium 3.5 vs Solar Pro 4
Solar Pro 4 leads Mistral Medium 3.5 on the Artificial Analysis Intelligence Index, 28.2 to 14.2, and Solar Pro 4 costs 12.5x less per output token ($0.60 vs $7.50 per million). Updated October 22, 2026; 43 benchmarks have a result for both.
Mistral Medium 3.5 or Solar Pro 4: which to pick
Only Mistral Medium 3.5 has a coding score, 25.5 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding.
Pick Solar Pro 4 for output tokens 12.5x cheaper ($0.60 vs $7.50 per million) and a larger context window (524K against 262K tokens).
- Shared results
- 43
- Mistral Medium 3.5 only
- 38
- Solar Pro 4 only
- 2
- 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 Mistral Medium 3.5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Solar Pro 4
Solar Pro 4 leads, 28.2 against 14.2.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Mistral Medium 3.5 has a AA Agentic Index result, 7.0.
Directional only
Reasoning
GPQA Diamond
No call
Only Mistral Medium 3.5 has a GPQA Diamond result, 34.9%.
Directional only
Knowledge
MMLU Pro
No call
Only Mistral Medium 3.5 has a MMLU Pro result, 75.3%.
Directional only
Web design
Design Arena: websites
Solar Pro 4
Solar Pro 4 leads, 1176 against 1142.
Same board, both measured
Long documents
Listed context window
Solar Pro 4
Solar Pro 4 takes 524K tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Solar Pro 4
Mistral Medium 3.5 $0.0053, Solar Pro 4 $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Mistral Medium 3.5 has the number, $6.02.
Directional only
At a glance
- Coding index
- Mistral Medium 3.5 25.5 from 3 benchmarks, Solar Pro 4 not benchmarked.
- Widest category
- Intelligence, 14.0 points apart on average over 1 shared benchmark.
- Widest single gap
- LMArena Text: Polish: Mistral Medium 3.5 1430 against Solar Pro 4 1304, 20.9 points apart on a 0 to 100 scale.
- Output price
- Mistral Medium 3.5 $7.50 against Solar Pro 4 $0.60 per million output tokens, 12.5x apart.
- Context window
- Mistral Medium 3.5 takes 262K 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 | Mistral Medium 3.5 | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 3 | 5 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 3 | 2 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| Web design | 0 | 6 | ||
| General | 16 | 1 | ||
| All shared boards | 28 | 15 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index35
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| LMArena WebDev | 1264 | 1371 | Solar Pro 4 |
| AA Coding Index | 46.9 | 52.7 | Solar Pro 4 |
| SWE-bench Verified (Vals AI) | 66.4% | Not measured | Only Mistral Medium 3.5 measured |
| Vibe Code Bench (Vals AI) | 2.9% | Not measured | Only Mistral Medium 3.5 measured |
| Code migration (Vals AI) | 5.1% | Not measured | Only Mistral Medium 3.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 39.0% | Not measured | Only Mistral Medium 3.5 measured |
| SciCode | 40.2% | 48.0% | Solar Pro 4 |
| Terminal-Bench Hard (Artificial Analysis run) | 33.3% | Not measured | Only Mistral Medium 3.5 measured |
| ALE-Bench | 764.0 | 179.3 | Mistral Medium 3.5 |
| LMArena Text: coding | 1460 | 1438 | Mistral Medium 3.5 |
| LMArena Text: software and IT | 1458 | 1431 | Mistral Medium 3.5 |
| LMArena WebDev: React | 1254 | 1363 | Solar Pro 4 |
| LMArena WebDev: HTML | 1308 | 1371 | Solar Pro 4 |
| Neither model has a result on the other 26 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 14.2 | 28.2 | Solar Pro 4 |
| Epoch Capabilities Index | 141.4 | Not measured | Only Mistral Medium 3.5 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Agentic Index | 7.0 | Not measured | Only Mistral Medium 3.5 measured |
| Design Arena: agents building web apps | Not measured | 1105 | Only Solar Pro 4 measured |
| Finance Agent (Vals AI) | 32.1% | Not measured | Only Mistral Medium 3.5 measured |
| Tax Agent Bench (Vals AI) | 4.5% | Not measured | Only Mistral Medium 3.5 measured |
| Legal Research Bench (Vals AI) | 9.1% | Not measured | Only Mistral Medium 3.5 measured |
| Excel Modeling Benchmark (Vals AI) | 11.2% | Not measured | Only Mistral Medium 3.5 measured |
| τ²-Bench Telecom | 94.2% | Not measured | Only Mistral Medium 3.5 measured |
| Neither model has a result on the other 34 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index32
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| GPQA Diamond | 34.9% | Not measured | Only Mistral Medium 3.5 measured |
| GPQA Diamond (Artificial Analysis run) | 74.8% | 89.1% | Solar Pro 4 |
| Humanity's Last Exam (Artificial Analysis run) | 13.8% | 29.8% | Solar Pro 4 |
| LMArena Text: hard prompts | 1436 | 1400 | Mistral Medium 3.5 |
| LMArena Text: expert | 1432 | 1428 | Mistral Medium 3.5 |
| LMArena Text: hard prompts in English | 1445 | 1427 | Mistral Medium 3.5 |
| LMArena Vision: diagrams | 1254 | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Vision: homework | 1230 | Not measured | Only Mistral Medium 3.5 measured |
| Kagi LLM Benchmark | 41.4% | Not measured | Only Mistral Medium 3.5 measured |
| Neither model has a result on the other 13 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| ProofBench | 9.0% | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Text: math | 1431 | 1421 | Mistral Medium 3.5 |
| LMArena Text: mathematical work | 1440 | 1427 | Mistral Medium 3.5 |
| Neither model has a result on the other 10 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 75.3% | Not measured | Only Mistral Medium 3.5 measured |
| CaseLaw (Vals AI) | 44.2% | Not measured | Only Mistral Medium 3.5 measured |
| CorpFin (Vals AI) | 58.8% | Not measured | Only Mistral Medium 3.5 measured |
| TaxEval (Vals AI) | 68.0% | Not measured | Only Mistral Medium 3.5 measured |
| MortgageTax (Vals AI) | 28.9% | Not measured | Only Mistral Medium 3.5 measured |
| MedCode (Vals AI) | 33.8% | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Text: science | 1428 | 1404 | Mistral Medium 3.5 |
| LMArena Text: medicine and healthcare | 1409 | 1374 | Mistral Medium 3.5 |
| LMArena Text: legal and government | 1437 | 1383 | Mistral Medium 3.5 |
| LMArena Text: business and finance | 1426 | 1381 | Mistral Medium 3.5 |
| Neither model has a result on the other 8 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1142 | 1176 | Solar Pro 4 |
| Design Arena: UI components | 1076 | 1147 | Solar Pro 4 |
| Design Arena: game dev | 1079 | 1169 | Solar Pro 4 |
| Design Arena: data viz | 1120 | 1177 | Solar Pro 4 |
| Design Arena: 3D | 1060 | 1178 | Solar Pro 4 |
| Design Arena: all code categories | 1121 | 1182 | Solar Pro 4 |
| Design Arena: SVG | 949 | Not measured | Only Mistral Medium 3.5 measured |
| Design Arena: ASCII art | 1062 | Not measured | Only Mistral Medium 3.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index161
| Benchmark | Mistral Medium 3.5 | Solar Pro 4 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 37.6% | Not measured | Only Mistral Medium 3.5 measured |
| MedScribe (Vals AI) | 67.7% | Not measured | Only Mistral Medium 3.5 measured |
| Vals Multimodal Index | 34.8% | Not measured | Only Mistral Medium 3.5 measured |
| IFBench | 68.8% | Not measured | Only Mistral Medium 3.5 measured |
| Long context reasoning (AA-LCR) | 69.3% | 70.7% | Solar Pro 4 |
| DTBench | 75.5% | Not measured | Only Mistral Medium 3.5 measured |
| LMCA | 26.1% | Not measured | Only Mistral Medium 3.5 measured |
| Surface Evolver Bench | 26.9% | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Text | 1421 | 1388 | Mistral Medium 3.5 |
| LMArena Text: instruction following | 1415 | 1375 | Mistral Medium 3.5 |
| LMArena Text: creative writing | 1374 | 1317 | Mistral Medium 3.5 |
| LMArena Vision | 1222 | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Text: English | 1433 | 1414 | Mistral Medium 3.5 |
| LMArena Text: non-English | 1404 | 1363 | Mistral Medium 3.5 |
| LMArena Text: Chinese | 1444 | 1422 | Mistral Medium 3.5 |
| LMArena Text: German | 1453 | 1358 | Mistral Medium 3.5 |
| LMArena Text: Japanese | Not measured | 1320 | Only Solar Pro 4 measured |
| LMArena Text: Korean | 1384 | 1383 | Mistral Medium 3.5 |
| LMArena Text: French | 1448 | 1400 | Mistral Medium 3.5 |
| LMArena Text: Spanish | 1411 | 1409 | Mistral Medium 3.5 |
| LMArena Text: Russian | 1395 | 1357 | Mistral Medium 3.5 |
| LMArena Text: Polish | 1430 | 1304 | Mistral Medium 3.5 |
| LMArena Text: multi-turn | 1423 | 1385 | Mistral Medium 3.5 |
| LMArena Text: longer queries | 1415 | 1382 | Mistral Medium 3.5 |
| LMArena Text: writing and language | 1384 | 1344 | Mistral Medium 3.5 |
| LMArena Text: entertainment and media | 1382 | 1332 | Mistral Medium 3.5 |
| LMArena Vision: English | 1240 | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Vision: Chinese | 1244 | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Vision: reading text | 1233 | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Vision: humor | 1216 | Not measured | Only Mistral Medium 3.5 measured |
| LMArena Vision: creative writing | 1198 | Not measured | Only Mistral Medium 3.5 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 | Mistral Medium 3.5 | 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 | Mistral Medium 3.5 | Upstage Solar Pro 4 |
|---|---|---|
| Maker | Mistral AI | Upstage |
| Weights | No public weights listed | No public weights listed |
| Released | April 30, 2026 | August 10, 2026 |
| Context window | 262K | 524K |
| Input $/Mtok | $1.50 | $0.15 |
| Output $/Mtok | $7.50 | $0.60 |
| Coding index | 25.5 | Not benchmarked |
| Independent measurements behind it | 3 | 1 |
| Cost per solved task | $6.02 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Mistral Medium 3.5 better than Solar Pro 4 for coding?
Only Mistral Medium 3.5 has a coding score, 25.5 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding. Pick Solar Pro 4 for output tokens 12.5x cheaper ($0.60 vs $7.50 per million) and a larger context window (524K against 262K tokens).
Which is cheaper, Mistral Medium 3.5 or Solar Pro 4?
Mistral Medium 3.5 costs $1.50 per million input tokens and $7.50 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for Mistral Medium 3.5 only.
Which has the bigger context window, Mistral Medium 3.5 or Solar Pro 4?
Solar Pro 4, with 524K tokens against 262K.
How many benchmarks is the Mistral Medium 3.5 vs Solar Pro 4 comparison based on?
43 benchmarks have a result for both models as of October 22, 2026. Mistral Medium 3.5's coding index rests on 3 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.