Claude Opus 5.5 vs Mistral Large 4
Claude Opus 5.5 leads Mistral Large 4 on coding, 88.8 to 56.4 on the Vibe Coding Index, and Mistral Large 4 costs 4.8x less per output token ($4.18 vs $20.00 per million). Updated October 22, 2026; 79 benchmarks have a result for both.
Claude Opus 5.5 or Mistral Large 4: which to pick
Pick Claude Opus 5.5 for coding: it scores 88.8 on the Vibe Coding Index against 56.4 for Mistral Large 4.
Pick Mistral Large 4 for output tokens 4.8x cheaper ($4.18 vs $20.00 per million) and a larger context window (1.05M against 1M tokens).
- Shared results
- 79
- Claude Opus 5.5 only
- 30
- Mistral Large 4 only
- 2
- 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 Opus 5.5
Claude Opus 5.5 scores 88.8 against 56.4.
5 benchmarks behind each score
Intelligence
AA Intelligence Index
Claude Opus 5.5
Claude Opus 5.5 leads, 57.6 against 38.4.
Same board, both measured
Web design
Design Arena: websites
Claude Opus 5.5
Claude Opus 5.5 leads, 1335 against 1257.
Same board, both measured
General
Vals Index
No call
Only Claude Opus 5.5 has a Vals Index result, 70.2%.
Directional only
Long documents
Listed context window
Mistral Large 4
Mistral Large 4 takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mistral Large 4
Claude Opus 5.5 $0.014, Mistral Large 4 $0.0034 per turn.
List prices
At a glance
- Coding index
- Claude Opus 5.5 88.8 from 5 benchmarks, Mistral Large 4 56.4 from 5 benchmarks.
- Widest category
- Math, 34.9 points apart on average over 6 shared benchmarks.
- Widest single gap
- ProofBench: Claude Opus 5.5 100.0% against Mistral Large 4 10.0%, 90.0 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 5.5 $20.00 against Mistral Large 4 $4.18 per million output tokens, 4.8x apart.
- Context window
- Claude Opus 5.5 takes 1M tokens, Mistral Large 4 1.05M.
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 Opus 5.5 | Bars | Mistral Large 4 | Ties |
|---|---|---|---|---|
| Coding | 15 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 8 | 1 | ||
| Reasoning | 10 | 0 | ||
| Math | 6 | 0 | ||
| Knowledge | 6 | 0 | ||
| Web design | 8 | 0 | ||
| General | 23 | 0 | ||
| All shared boards | 78 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index150
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| LiveBench coding | 96.3% | 60.0% | Claude Opus 5.5 |
| LMArena WebDev | 1807 | 1543 | Claude Opus 5.5 |
| Terminal-Bench 4 (Vals AI) | 65.2% | 27.8% | Claude Opus 5.5 |
| Vibe Code Bench (Vals AI) | 90.3% | 78.4% | Claude Opus 5.5 |
| Code migration (Vals AI) | 66.7% | 30.6% | Claude Opus 5.5 |
| ProgramBench (Vals AI) | 18.5% | Not measured | Only Claude Opus 5.5 measured |
| IOI (Vals AI) | 95.1% | 45.3% | Claude Opus 5.5 |
| Terminal-Bench 2.1 (Vals AI) | 87.6% | Not measured | Only Claude Opus 5.5 measured |
| SWE-bench Multimodal (Vals AI) | 70.2% | 33.1% | Claude Opus 5.5 |
| Vibe Code Bench 1-100 (Vals AI) | 30.4% | 14.3% | Claude Opus 5.5 |
| CyberBench (Vals AI) | 74.6% | Not measured | Only Claude Opus 5.5 measured |
| SciCode | 66.9% | 54.2% | Claude Opus 5.5 |
| FrontierCode | 54.6% | 39.4% | Claude Opus 5.5 |
| FrontierSWE | 62.3% | Not measured | Only Claude Opus 5.5 measured |
| MirrorCode | 77.4% | Not measured | Only Claude Opus 5.5 measured |
| ALE-Bench | 2147.4 | 1213.2 | Claude Opus 5.5 |
| LMArena Text: coding | 1545 | 1478 | Claude Opus 5.5 |
| LMArena Text: software and IT | 1538 | 1467 | Claude Opus 5.5 |
| LMArena WebDev: React | 1855 | 1559 | Claude Opus 5.5 |
| LMArena WebDev: HTML | 1753 | 1487 | Claude Opus 5.5 |
| LMArena WebDev: from an image | 1753 | Not measured | Only Claude Opus 5.5 measured |
| SciCode | 18.5% | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 17 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 57.6 | 38.4 | Claude Opus 5.5 |
| Epoch Capabilities Index | 168.8 | 150.0 | Claude Opus 5.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index81
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1316 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: agents building mobile apps | 1308 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: spreadsheets | 1368 | Not measured | Only Claude Opus 5.5 measured |
| LiveBench research | 85.0% | 28.1% | Claude Opus 5.5 |
| LiveBench browser | 80.0% | 8.0% | Claude Opus 5.5 |
| LiveBench long agentic | 85.0% | 11.8% | Claude Opus 5.5 |
| SREBench (Vals AI) | 33.6% | Not measured | Only Claude Opus 5.5 measured |
| Finance Agent (Vals AI) | 58.6% | 54.7% | Claude Opus 5.5 |
| Tax Agent Bench (Vals AI) | 45.6% | 30.4% | Claude Opus 5.5 |
| Legal Research Bench (Vals AI) | 50.5% | 31.7% | Claude Opus 5.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 9.2% | 17.5% | Mistral Large 4 |
| Excel Modeling Benchmark (Vals AI) | 75.9% | 56.2% | Claude Opus 5.5 |
| BioMysteryBench (Vals AI) | 79.3% | 67.0% | Claude Opus 5.5 |
| Terminal-Bench-Science (Vals AI) | 47.1% | Not measured | Only Claude Opus 5.5 measured |
| Vals Science Index | 58.7% | Not measured | Only Claude Opus 5.5 measured |
| Time Horizon Index (Vals AI) | 91.3% | Not measured | Only Claude Opus 5.5 measured |
| CUA-bench (Vals AI) | 14.0% | Not measured | Only Claude Opus 5.5 measured |
| Robo-bench (Vals AI) | 14.6% | Not measured | Only Claude Opus 5.5 measured |
| APEX-Agents | 73.5% | Not measured | Only Claude Opus 5.5 measured |
| Remote Labor Index | 21.3% | Not measured | Only Claude Opus 5.5 measured |
| SpireClimb | 3.3% | Not measured | Only Claude Opus 5.5 measured |
| Vending-Bench 2 | $9,235 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Search | 1213 | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index100
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| LiveBench reasoning | 92.2% | 83.9% | Claude Opus 5.5 |
| MysteryMechanism (Vals AI) | 49.5% | 12.2% | Claude Opus 5.5 |
| Humanity's Last Exam (Artificial Analysis run) | 61.4% | 35.0% | Claude Opus 5.5 |
| GPQA Diamond (Epoch AI run) | 90.6% | 88.1% | Claude Opus 5.5 |
| ARC-AGI | 98.5% | Not measured | Only Claude Opus 5.5 measured |
| ARC-AGI-2 | 93.3% | Not measured | Only Claude Opus 5.5 measured |
| Chess puzzles | 67.0% | 33.0% | Claude Opus 5.5 |
| Mystery game puzzles | 71.0% | 17.0% | Claude Opus 5.5 |
| EBR-bench | 71.4% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: hard prompts | 1536 | 1444 | Claude Opus 5.5 |
| LMArena Text: expert | 1549 | 1444 | Claude Opus 5.5 |
| LMArena Text: hard prompts in English | 1535 | 1442 | Claude Opus 5.5 |
| LMArena Vision: diagrams | 1345 | 1288 | Claude Opus 5.5 |
| LMArena Vision: homework | 1362 | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 8 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | 98.3% | Claude Opus 5.5 |
| FrontierMath, tiers 1 to 3 | 91.2% | 58.6% | Claude Opus 5.5 |
| FrontierMath, tier 4 | 95.0% | 26.8% | Claude Opus 5.5 |
| ProofBench | 100.0% | 10.0% | Claude Opus 5.5 |
| LMArena Text: math | 1518 | 1469 | Claude Opus 5.5 |
| LMArena Text: mathematical work | 1516 | 1462 | Claude Opus 5.5 |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| MedCode (Vals AI) | 49.8% | 40.7% | Claude Opus 5.5 |
| SimpleQA Verified | 72.2% | 20.0% | Claude Opus 5.5 |
| LMArena Text: science | 1524 | 1448 | Claude Opus 5.5 |
| LMArena Text: medicine and healthcare | 1509 | 1433 | Claude Opus 5.5 |
| LMArena Text: legal and government | 1518 | 1425 | Claude Opus 5.5 |
| LMArena Text: business and finance | 1494 | 1439 | Claude Opus 5.5 |
| FACTS Benchmark Suite | 65.3% | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 11 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1335 | 1257 | Claude Opus 5.5 |
| Design Arena: UI components | 1385 | 1272 | Claude Opus 5.5 |
| Design Arena: game dev | 1461 | 1225 | Claude Opus 5.5 |
| Design Arena: data viz | 1397 | 1275 | Claude Opus 5.5 |
| Design Arena: 3D | 1476 | 1252 | Claude Opus 5.5 |
| Design Arena: all code categories | 1390 | 1259 | Claude Opus 5.5 |
| Design Arena: SVG | 1329 | 1232 | Claude Opus 5.5 |
| Design Arena: ASCII art | Not measured | 1202 | Only Mistral Large 4 measured |
| LiveBench design | 86.9% | 65.6% | Claude Opus 5.5 |
GeneralLike-for-likePublic boards, shown as published, kept out of the index230
| Benchmark | Claude Opus 5.5 | Mistral Large 4 | Leader |
|---|---|---|---|
| Vals Index | 70.2% | Not measured | Only Claude Opus 5.5 measured |
| LiveBench data analysis | 80.3% | 76.5% | Claude Opus 5.5 |
| Public Benefits Bench (Vals AI) | 70.6% | Not measured | Only Claude Opus 5.5 measured |
| SAGE (Vals AI) | 45.8% | Not measured | Only Claude Opus 5.5 measured |
| MedScribe (Vals AI) | 91.4% | 80.4% | Claude Opus 5.5 |
| Long context reasoning (AA-LCR) | 84.7% | 81.3% | Claude Opus 5.5 |
| DTBench | 98.9% | 88.2% | Claude Opus 5.5 |
| LMCA | 68.2% | 35.8% | Claude Opus 5.5 |
| Surface Evolver Bench | Not measured | 28.1% | Only Mistral Large 4 measured |
| Furniture assembly | 83.3% | 20.8% | Claude Opus 5.5 |
| LMArena Text | 1516 | 1431 | Claude Opus 5.5 |
| LMArena Text: instruction following | 1537 | 1422 | Claude Opus 5.5 |
| LMArena Text: creative writing | 1535 | 1363 | Claude Opus 5.5 |
| LMArena Vision | 1321 | 1272 | Claude Opus 5.5 |
| LMArena Text: English | 1519 | 1433 | Claude Opus 5.5 |
| LMArena Text: non-English | 1507 | 1422 | Claude Opus 5.5 |
| LMArena Text: Chinese | 1582 | 1492 | Claude Opus 5.5 |
| LMArena Text: Japanese | 1534 | 1415 | Claude Opus 5.5 |
| LMArena Text: French | 1493 | 1492 | Claude Opus 5.5 |
| LMArena Text: Spanish | 1508 | 1455 | Claude Opus 5.5 |
| LMArena Text: Russian | 1517 | 1417 | Claude Opus 5.5 |
| LMArena Text: multi-turn | 1501 | 1435 | Claude Opus 5.5 |
| LMArena Text: longer queries | 1532 | 1428 | Claude Opus 5.5 |
| LMArena Text: writing and language | 1532 | 1386 | Claude Opus 5.5 |
| LMArena Text: entertainment and media | 1515 | 1378 | Claude Opus 5.5 |
| LMArena Vision: English | 1317 | 1283 | Claude Opus 5.5 |
| LMArena Vision: reading text | 1326 | 1284 | Claude Opus 5.5 |
| LMArena Vision: creative writing | 1320 | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 18 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 5.5 | Mistral Large 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
Mistral Large 4 costs less
Repository review
50K input + 3K output tokens
Mistral Large 4 costs less
Agent loop
200K input + 10K output tokens
Mistral Large 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 | Anthropic Claude Opus 5.5 | Mistral Large 4 |
|---|---|---|
| Maker | Anthropic | Mistral AI |
| Weights | No public weights listed | No public weights listed |
| Released | September 22, 2026 | October 6, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $4.00 | $1.36 |
| Output $/Mtok | $20.00 | $4.18 |
| Coding index | 88.8 | 56.4 |
| Independent measurements behind it | 5 | 5 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 5.5 better than Mistral Large 4 for coding?
Pick Claude Opus 5.5 for coding: it scores 88.8 on the Vibe Coding Index against 56.4 for Mistral Large 4. Pick Mistral Large 4 for output tokens 4.8x cheaper ($4.18 vs $20.00 per million) and a larger context window (1.05M against 1M tokens).
Which is cheaper, Claude Opus 5.5 or Mistral Large 4?
Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; Mistral Large 4 costs $1.36 and $4.18. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Opus 5.5 or Mistral Large 4?
Mistral Large 4, with 1.05M tokens against 1M.
How many benchmarks is the Claude Opus 5.5 vs Mistral Large 4 comparison based on?
79 benchmarks have a result for both models as of October 22, 2026. Claude Opus 5.5's coding index rests on 5 independent benchmarks and Mistral Large 4's on 5. Where only one model has a result, the page says so instead of naming a winner.