Claude Sonnet 4.5 vs Mistral Medium 3.5
Claude Sonnet 4.5 leads Mistral Medium 3.5 on coding, 39.5 to 25.5 on the Vibe Coding Index, and Mistral Medium 3.5 costs 2.0x less per output token ($7.50 vs $15.00 per million). Updated October 22, 2026; 57 benchmarks have a result for both.
Claude Sonnet 4.5 or Mistral Medium 3.5: which to pick
Pick Claude Sonnet 4.5 for coding: it scores 39.5 on the Vibe Coding Index against 25.5 for Mistral Medium 3.5.
Pick Mistral Medium 3.5 for output tokens 2.0x cheaper ($7.50 vs $15.00 per million) and work measured by SAGE (Vals AI) or LMArena Text: German, where it leads.
- Shared results
- 57
- Claude Sonnet 4.5 only
- 38
- Mistral Medium 3.5 only
- 24
- Like-for-like categories
- 8 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
Claude Sonnet 4.5
Claude Sonnet 4.5 scores 39.5 against 25.5.
3 benchmarks behind each score
Intelligence
AA Intelligence Index
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 20.7 against 14.2.
Same board, both measured
Agentic work
AA Agentic Index
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 15.8 against 7.0.
Same board, both measured
Reasoning
GPQA Diamond
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 81.6% against 34.9%.
Same board, both measured
Math
AIME
No call
Only Claude Sonnet 4.5 has a AIME result, 88.2%.
Directional only
Knowledge
MMLU Pro
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 87.4% against 75.3%.
Same board, both measured
Web design
Design Arena: websites
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 1189 against 1142.
Same board, both measured
Long documents
Listed context window
Claude Sonnet 4.5
Claude Sonnet 4.5 takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mistral Medium 3.5
Claude Sonnet 4.5 $0.011, Mistral Medium 3.5 $0.0053 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Claude Sonnet 4.5
Claude Sonnet 4.5 $1.16, Mistral Medium 3.5 $6.02.
Published attempt cost and pass rate
At a glance
- Coding index
- Claude Sonnet 4.5 39.5 from 3 benchmarks, Mistral Medium 3.5 25.5 from 3 benchmarks.
- Widest category
- Reasoning, 16.1 points apart on average over 5 shared benchmarks.
- Widest single gap
- GPQA Diamond: Claude Sonnet 4.5 81.6% against Mistral Medium 3.5 34.9%, 46.8 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 4.5 $15.00 against Mistral Medium 3.5 $7.50 per million output tokens, 2.0x apart.
- Context window
- Claude Sonnet 4.5 takes 1M tokens, Mistral Medium 3.5 262K.
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 | Claude Sonnet 4.5 | Bars | Mistral Medium 3.5 | Ties |
|---|---|---|---|---|
| Coding | 8 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 5 | 0 | ||
| Math | 3 | 0 | ||
| Knowledge | 10 | 0 | ||
| Web design | 8 | 0 | ||
| General | 17 | 3 | ||
| All shared boards | 54 | 3 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index80
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| SWE-bench Verified | 74.8% | Not measured | Only Claude Sonnet 4.5 measured |
| SWE-bench Multilingual | 67.0% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena WebDev | 1394 | 1264 | Claude Sonnet 4.5 |
| AA Coding Index | 52.1 | 46.9 | Claude Sonnet 4.5 |
| LiveCodeBench (Vals AI) | 73.0% | Not measured | Only Claude Sonnet 4.5 measured |
| SWE-bench Verified (Vals AI) | 70.0% | 66.4% | Claude Sonnet 4.5 |
| Vibe Code Bench (Vals AI) | 22.6% | 2.9% | Claude Sonnet 4.5 |
| Code migration (Vals AI) | Not measured | 5.1% | Only Mistral Medium 3.5 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 39.0% | Only Mistral Medium 3.5 measured |
| SciCode | Not measured | 40.2% | Only Mistral Medium 3.5 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 33.3% | Only Mistral Medium 3.5 measured |
| Terminal-Bench | 46.5% | Not measured | Only Claude Sonnet 4.5 measured |
| GSO-Bench | 14.7% | Not measured | Only Claude Sonnet 4.5 measured |
| WeirdML | 47.7% | Not measured | Only Claude Sonnet 4.5 measured |
| Cybench | 60.0% | Not measured | Only Claude Sonnet 4.5 measured |
| ALE-Bench | Not measured | 764.0 | Only Mistral Medium 3.5 measured |
| LMArena Text: coding | 1488 | 1460 | Claude Sonnet 4.5 |
| LMArena Text: software and IT | 1473 | 1458 | Claude Sonnet 4.5 |
| LMArena WebDev: React | 1386 | 1254 | Claude Sonnet 4.5 |
| LMArena WebDev: HTML | 1399 | 1308 | Claude Sonnet 4.5 |
| Neither model has a result on the other 19 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.7 | 14.2 | Claude Sonnet 4.5 |
| Epoch Capabilities Index | 146.7 | 141.4 | Claude Sonnet 4.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| AA Agentic Index | 15.8 | 7.0 | Claude Sonnet 4.5 |
| Design Arena: agents building web apps | 1060 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: agents building full-stack apps | 1050 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: agents building mobile apps | 1137 | Not measured | Only Claude Sonnet 4.5 measured |
| Finance Agent (Vals AI) | Not measured | 32.1% | Only Mistral Medium 3.5 measured |
| Tax Agent Bench (Vals AI) | Not measured | 4.5% | Only Mistral Medium 3.5 measured |
| Legal Research Bench (Vals AI) | Not measured | 9.1% | Only Mistral Medium 3.5 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 11.2% | Only Mistral Medium 3.5 measured |
| τ²-Bench Telecom | Not measured | 94.2% | Only Mistral Medium 3.5 measured |
| METR time horizons | 67.4% | Not measured | Only Claude Sonnet 4.5 measured |
| Remote Labor Index | 2.1% | Not measured | Only Claude Sonnet 4.5 measured |
| GDPval | 42.5% | Not measured | Only Claude Sonnet 4.5 measured |
| DeepResearch Bench | 52.6% | Not measured | Only Claude Sonnet 4.5 measured |
| OSWorld | 62.9% | Not measured | Only Claude Sonnet 4.5 measured |
| Vending-Bench 2 | $3,839 | Not measured | Only Claude Sonnet 4.5 measured |
| Berkeley Function Calling Leaderboard (BFCL) | 73.2% | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 25 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| GPQA Diamond | 81.6% | 34.9% | Claude Sonnet 4.5 |
| MMMU Pro (Vals AI) | 79.3% | Not measured | Only Claude Sonnet 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 74.8% | Only Mistral Medium 3.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 13.8% | Only Mistral Medium 3.5 measured |
| GPQA Diamond (Epoch AI run) | 82.3% | Not measured | Only Claude Sonnet 4.5 measured |
| ARC-AGI | 63.7% | Not measured | Only Claude Sonnet 4.5 measured |
| ARC-AGI-2 | 13.6% | Not measured | Only Claude Sonnet 4.5 measured |
| SimpleBench | 54.3% | Not measured | Only Claude Sonnet 4.5 measured |
| Chess puzzles | 10.0% | Not measured | Only Claude Sonnet 4.5 measured |
| Mystery game puzzles | 17.0% | Not measured | Only Claude Sonnet 4.5 measured |
| EBR-bench | 2.4% | Not measured | Only Claude Sonnet 4.5 measured |
| VPCT | 39.8% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: hard prompts | 1462 | 1436 | Claude Sonnet 4.5 |
| LMArena Text: expert | 1483 | 1432 | Claude Sonnet 4.5 |
| LMArena Text: hard prompts in English | 1471 | 1445 | Claude Sonnet 4.5 |
| LMArena Vision: diagrams | Not measured | 1254 | Only Mistral Medium 3.5 measured |
| LMArena Vision: homework | Not measured | 1230 | Only Mistral Medium 3.5 measured |
| Kagi LLM Benchmark | 57.9% | 41.4% | Claude Sonnet 4.5 |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| AIME | 88.2% | Not measured | Only Claude Sonnet 4.5 measured |
| MGSM (Vals AI) | 94.3% | Not measured | Only Claude Sonnet 4.5 measured |
| OTIS Mock AIME | 77.8% | Not measured | Only Claude Sonnet 4.5 measured |
| FrontierMath, tiers 1 to 3 | 23.9% | Not measured | Only Claude Sonnet 4.5 measured |
| FrontierMath, tier 4 | 2.4% | Not measured | Only Claude Sonnet 4.5 measured |
| ProofBench | 19.0% | 9.0% | Claude Sonnet 4.5 |
| MATH level 5 | 97.7% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: math | 1449 | 1431 | Claude Sonnet 4.5 |
| LMArena Text: mathematical work | 1462 | 1440 | Claude Sonnet 4.5 |
| Neither model has a result on the other 4 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index100
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| MMLU Pro | 87.4% | 75.3% | Claude Sonnet 4.5 |
| LegalBench (Vals AI) | 84.1% | Not measured | Only Claude Sonnet 4.5 measured |
| CaseLaw (Vals AI) | 62.2% | 44.2% | Claude Sonnet 4.5 |
| CorpFin (Vals AI) | 62.0% | 58.8% | Claude Sonnet 4.5 |
| TaxEval (Vals AI) | 73.3% | 68.0% | Claude Sonnet 4.5 |
| MortgageTax (Vals AI) | 64.0% | 28.9% | Claude Sonnet 4.5 |
| MedQA (Vals AI) | 94.7% | Not measured | Only Claude Sonnet 4.5 measured |
| MedCode (Vals AI) | 44.1% | 33.8% | Claude Sonnet 4.5 |
| SimpleQA Verified | 30.7% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: science | 1448 | 1428 | Claude Sonnet 4.5 |
| LMArena Text: medicine and healthcare | 1444 | 1409 | Claude Sonnet 4.5 |
| LMArena Text: legal and government | 1451 | 1437 | Claude Sonnet 4.5 |
| LMArena Text: business and finance | 1440 | 1426 | Claude Sonnet 4.5 |
| FACTS Benchmark Suite | 40.6% | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| Design Arena: websites | 1189 | 1142 | Claude Sonnet 4.5 |
| Design Arena: UI components | 1170 | 1076 | Claude Sonnet 4.5 |
| Design Arena: game dev | 1166 | 1079 | Claude Sonnet 4.5 |
| Design Arena: data viz | 1167 | 1120 | Claude Sonnet 4.5 |
| Design Arena: 3D | 1157 | 1060 | Claude Sonnet 4.5 |
| Design Arena: all code categories | 1182 | 1121 | Claude Sonnet 4.5 |
| Design Arena: SVG | 1115 | 949 | Claude Sonnet 4.5 |
| Design Arena: ASCII art | 1205 | 1062 | Claude Sonnet 4.5 |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index173
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 36.1% | 37.6% | Mistral Medium 3.5 |
| MedScribe (Vals AI) | 84.5% | 67.7% | Claude Sonnet 4.5 |
| Vals Multimodal Index | Not measured | 34.8% | Only Mistral Medium 3.5 measured |
| IFBench | Not measured | 68.8% | Only Mistral Medium 3.5 measured |
| Long context reasoning (AA-LCR) | Not measured | 69.3% | Only Mistral Medium 3.5 measured |
| DTBench | 83.2% | 75.5% | Claude Sonnet 4.5 |
| LMCA | 38.8% | 26.1% | Claude Sonnet 4.5 |
| Surface Evolver Bench | Not measured | 26.9% | Only Mistral Medium 3.5 measured |
| LMArena Text | 1438 | 1421 | Claude Sonnet 4.5 |
| LMArena Text: instruction following | 1459 | 1415 | Claude Sonnet 4.5 |
| LMArena Text: creative writing | 1442 | 1374 | Claude Sonnet 4.5 |
| LMArena Vision | Not measured | 1222 | Only Mistral Medium 3.5 measured |
| LMArena Text: English | 1450 | 1433 | Claude Sonnet 4.5 |
| LMArena Text: non-English | 1425 | 1404 | Claude Sonnet 4.5 |
| LMArena Text: Chinese | 1460 | 1444 | Claude Sonnet 4.5 |
| LMArena Text: German | 1427 | 1453 | Mistral Medium 3.5 |
| LMArena Text: Japanese | 1390 | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: Korean | 1402 | 1384 | Claude Sonnet 4.5 |
| LMArena Text: French | 1459 | 1448 | Claude Sonnet 4.5 |
| LMArena Text: Spanish | 1458 | 1411 | Claude Sonnet 4.5 |
| LMArena Text: Russian | 1437 | 1395 | Claude Sonnet 4.5 |
| LMArena Text: Polish | 1423 | 1430 | Mistral Medium 3.5 |
| LMArena Text: multi-turn | 1465 | 1423 | Claude Sonnet 4.5 |
| LMArena Text: longer queries | 1475 | 1415 | Claude Sonnet 4.5 |
| LMArena Text: writing and language | 1442 | 1384 | Claude Sonnet 4.5 |
| LMArena Text: entertainment and media | 1428 | 1382 | Claude Sonnet 4.5 |
| LMArena Vision: English | Not measured | 1240 | Only Mistral Medium 3.5 measured |
| LMArena Vision: Chinese | Not measured | 1244 | Only Mistral Medium 3.5 measured |
| LMArena Vision: reading text | Not measured | 1233 | Only Mistral Medium 3.5 measured |
| LMArena Vision: humor | Not measured | 1216 | Only Mistral Medium 3.5 measured |
| LMArena Vision: creative writing | Not measured | 1198 | Only Mistral Medium 3.5 measured |
| LMArena Document | 1450 | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 4.5 | Mistral Medium 3.5 | 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
Mistral Medium 3.5 costs less
Repository review
50K input + 3K output tokens
Mistral Medium 3.5 costs less
Agent loop
200K input + 10K output tokens
Mistral Medium 3.5 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 | Anthropic Claude Sonnet 4.5 | Mistral Medium 3.5 |
|---|---|---|
| Maker | Anthropic | Mistral AI |
| Weights | No public weights listed | No public weights listed |
| Released | September 29, 2025 | April 30, 2026 |
| Context window | 1M | 262K |
| Input $/Mtok | $3.00 | $1.50 |
| Output $/Mtok | $15.00 | $7.50 |
| Coding index | 39.5 | 25.5 |
| Independent measurements behind it | 3 | 3 |
| Cost per solved task | $1.16 | $6.02 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 4.5 better than Mistral Medium 3.5 for coding?
Pick Claude Sonnet 4.5 for coding: it scores 39.5 on the Vibe Coding Index against 25.5 for Mistral Medium 3.5. Pick Mistral Medium 3.5 for output tokens 2.0x cheaper ($7.50 vs $15.00 per million) and work measured by SAGE (Vals AI) or LMArena Text: German, where it leads.
Which is cheaper, Claude Sonnet 4.5 or Mistral Medium 3.5?
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens; Mistral Medium 3.5 costs $1.50 and $7.50. Per solved SWE-bench Verified task, Claude Sonnet 4.5 costs $1.16 and Mistral Medium 3.5 $6.02.
Which has the bigger context window, Claude Sonnet 4.5 or Mistral Medium 3.5?
Claude Sonnet 4.5, with 1M tokens against 262K.
How many benchmarks is the Claude Sonnet 4.5 vs Mistral Medium 3.5 comparison based on?
57 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 4.5's coding index rests on 3 independent benchmarks and Mistral Medium 3.5's on 3. Where only one model has a result, the page says so instead of naming a winner.