Claude Opus 4.6 vs Claude Sonnet 5.5
Claude Sonnet 5.5 leads Claude Opus 4.6 on coding, 87.3 to 57.2 on the Vibe Coding Index, and Claude Sonnet 5.5 costs 2.5x less per output token ($10.00 vs $25.00 per million). Updated October 22, 2026; 64 benchmarks have a result for both.
vs boards won of 64 shared
Claude Opus 4.6 or Claude Sonnet 5.5: which to pick
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 57.2 for Claude Opus 4.6.
Pick Claude Opus 4.6 for work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.
Model AClaude Opus 4.6Anthropic57.2/1004 independent benchmarks$1.56 per solved taskModel BClaude Sonnet 5.5Anthropic87.3/1005 independent benchmarksNo cost per solved task
- Shared results
- 64
- Claude Opus 4.6 only
- 46
- Claude Sonnet 5.5 only
- 32
- 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 5.5
Claude Sonnet 5.5 scores 87.3 against 57.2.
4 and 5 benchmarks behind the scores
Intelligence
AA Intelligence Index
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 56.0 against 31.9.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.6 has a GPQA Diamond result, 89.7%.
Directional only
Math
AIME
No call
Only Claude Opus 4.6 has a AIME result, 95.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Opus 4.6 has a MMLU Pro result, 89.1%.
Directional only
Web design
Design Arena: websites
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 1327 against 1291.
Same board, both measured
General
Vals Index
No call
Only Claude Sonnet 5.5 has a Vals Index result, 70.8%.
Directional only
Long documents
Listed context window
No call
Both take 1M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Claude Sonnet 5.5
Claude Opus 4.6 $0.018, Claude Sonnet 5.5 $0.0070 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Opus 4.6 has the number, $1.56.
Directional only
At a glance
- Coding index
- Claude Opus 4.6 57.2 from 4 benchmarks, Claude Sonnet 5.5 87.3 from 5 benchmarks.
- Widest category
- Math, 23.0 points apart on average over 6 shared benchmarks.
- Widest single gap
- FrontierMath, tier 4: Claude Opus 4.6 26.8% against Claude Sonnet 5.5 80.5%, 53.7 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.6 $25.00 against Claude Sonnet 5.5 $10.00 per million output tokens, 2.5x apart.
- Context window
- Both take 1M tokens.
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 4.6 | Bars | Claude Sonnet 5.5 | Ties |
|---|---|---|---|---|
| Coding | 2 | 6 | ||
| Intelligence | 0 | 2 | ||
| Agentic work | 0 | 4 | ||
| Reasoning | 5 | 4 | ||
| Math | 2 | 4 | ||
| Knowledge | 5 | 1 | ||
| Web design | 0 | 6 | ||
| General | 17 | 6 | ||
| All shared boards | 31 | 33 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index26
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| SWE-bench Verified | 75.6% | Not measured | Only Claude Opus 4.6 measured |
| SWE-bench Multilingual | 72.0% | Not measured | Only Claude Opus 4.6 measured |
| LiveBench coding | Not measured | 94.7% | Only Claude Sonnet 5.5 measured |
| LMArena WebDev | 1547 | 1768 | Claude Sonnet 5.5 |
| LiveCodeBench (Vals AI) | 84.7% | Not measured | Only Claude Opus 4.6 measured |
| SWE-bench Verified (Vals AI) | 78.2% | Not measured | Only Claude Opus 4.6 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 64.1% | Only Claude Sonnet 5.5 measured |
| Vibe Code Bench (Vals AI) | 57.6% | 92.4% | Claude Sonnet 5.5 |
| Code migration (Vals AI) | Not measured | 69.8% | Only Claude Sonnet 5.5 measured |
| ProgramBench (Vals AI) | Not measured | 6.5% | Only Claude Sonnet 5.5 measured |
| IOI (Vals AI) | Not measured | 83.1% | Only Claude Sonnet 5.5 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 83.2% | Only Claude Sonnet 5.5 measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 58.3% | Only Claude Sonnet 5.5 measured |
| CyberBench (Vals AI) | Not measured | 59.6% | Only Claude Sonnet 5.5 measured |
| SciCode | Not measured | 61.0% | Only Claude Sonnet 5.5 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 48.5% | Not measured | Only Claude Opus 4.6 measured |
| Terminal-Bench | 79.8% | Not measured | Only Claude Opus 4.6 measured |
| FrontierCode | 26.6% | 52.1% | Claude Sonnet 5.5 |
| FrontierSWE | Not measured | 61.9% | Only Claude Sonnet 5.5 measured |
| GSO-Bench | 41.2% | Not measured | Only Claude Opus 4.6 measured |
| WeirdML | 78.0% | Not measured | Only Claude Opus 4.6 measured |
| Cybench | 93.0% | Not measured | Only Claude Opus 4.6 measured |
| ALE-Bench | Not measured | 1819.1 | Only Claude Sonnet 5.5 measured |
| LMArena Text: coding | 1534 | 1513 | Claude Opus 4.6 |
| LMArena Text: software and IT | 1527 | 1504 | Claude Opus 4.6 |
| LMArena WebDev: React | 1539 | 1817 | Claude Sonnet 5.5 |
| LMArena WebDev: HTML | 1559 | 1741 | Claude Sonnet 5.5 |
| LMArena WebDev: from an image | 1543 | 1737 | Claude Sonnet 5.5 |
| SciCode | Not measured | 13.8% | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 10 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| AA Intelligence Index | 31.9 | 56.0 | Claude Sonnet 5.5 |
| Epoch Capabilities Index | 155.7 | 166.2 | Claude Sonnet 5.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1206 | 1305 | Claude Sonnet 5.5 |
| Design Arena: agents building full-stack apps | 1220 | Not measured | Only Claude Opus 4.6 measured |
| Design Arena: agents building mobile apps | 1207 | 1262 | Claude Sonnet 5.5 |
| Design Arena: agents building Android apps | 1197 | Not measured | Only Claude Opus 4.6 measured |
| Design Arena: agents building games | 1212 | Not measured | Only Claude Opus 4.6 measured |
| Design Arena: spreadsheets | Not measured | 1273 | Only Claude Sonnet 5.5 measured |
| LiveBench research | Not measured | 83.6% | Only Claude Sonnet 5.5 measured |
| LiveBench browser | Not measured | 84.0% | Only Claude Sonnet 5.5 measured |
| LiveBench long agentic | Not measured | 78.8% | Only Claude Sonnet 5.5 measured |
| SREBench (Vals AI) | Not measured | 30.1% | Only Claude Sonnet 5.5 measured |
| Finance Agent (Vals AI) | Not measured | 58.1% | Only Claude Sonnet 5.5 measured |
| Tax Agent Bench (Vals AI) | Not measured | 42.0% | Only Claude Sonnet 5.5 measured |
| Legal Research Bench (Vals AI) | Not measured | 48.1% | Only Claude Sonnet 5.5 measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 10.4% | Only Claude Sonnet 5.5 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 75.7% | Only Claude Sonnet 5.5 measured |
| BioMysteryBench (Vals AI) | Not measured | 81.1% | Only Claude Sonnet 5.5 measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 47.1% | Only Claude Sonnet 5.5 measured |
| Vals Science Index | Not measured | 59.1% | Only Claude Sonnet 5.5 measured |
| τ²-Bench Telecom | 92.1% | Not measured | Only Claude Opus 4.6 measured |
| APEX-Agents | 46.3% | 75.5% | Claude Sonnet 5.5 |
| METR time horizons | 78.9% | Not measured | Only Claude Opus 4.6 measured |
| Remote Labor Index | 4.2% | Not measured | Only Claude Opus 4.6 measured |
| DeepResearch Bench | 55.3% | Not measured | Only Claude Opus 4.6 measured |
| SpireClimb | Not measured | 1.3% | Only Claude Sonnet 5.5 measured |
| Vending-Bench 2 | $8,018 | $11,165 | Claude Sonnet 5.5 |
| Neither model has a result on the other 16 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index54
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| GPQA Diamond | 89.7% | Not measured | Only Claude Opus 4.6 measured |
| LiveBench reasoning | Not measured | 91.6% | Only Claude Sonnet 5.5 measured |
| MysteryMechanism (Vals AI) | Not measured | 49.1% | Only Claude Sonnet 5.5 measured |
| MMMU Pro (Vals AI) | 83.9% | Not measured | Only Claude Opus 4.6 measured |
| GPQA Diamond (Artificial Analysis run) | 89.6% | Not measured | Only Claude Opus 4.6 measured |
| Humanity's Last Exam (Artificial Analysis run) | 39.9% | 55.0% | Claude Sonnet 5.5 |
| GPQA Diamond (Epoch AI run) | 90.5% | 95.6% | Claude Sonnet 5.5 |
| ARC-AGI | 94.0% | Not measured | Only Claude Opus 4.6 measured |
| ARC-AGI-2 | 69.2% | Not measured | Only Claude Opus 4.6 measured |
| SimpleBench | 67.6% | Not measured | Only Claude Opus 4.6 measured |
| Chess puzzles | 21.0% | 59.0% | Claude Sonnet 5.5 |
| Mystery game puzzles | 25.0% | 65.0% | Claude Sonnet 5.5 |
| EBR-bench | 12.7% | Not measured | Only Claude Opus 4.6 measured |
| LMArena Text: hard prompts | 1525 | 1494 | Claude Opus 4.6 |
| LMArena Text: expert | 1544 | 1531 | Claude Opus 4.6 |
| LMArena Text: hard prompts in English | 1530 | 1502 | Claude Opus 4.6 |
| LMArena Vision: diagrams | 1340 | 1329 | Claude Opus 4.6 |
| LMArena Vision: homework | 1337 | 1331 | Claude Opus 4.6 |
| Kagi LLM Benchmark | 83.6% | Not measured | Only Claude Opus 4.6 measured |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index24
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| AIME | 95.6% | Not measured | Only Claude Opus 4.6 measured |
| OTIS Mock AIME | 94.4% | 100.0% | Claude Sonnet 5.5 |
| FrontierMath, tiers 1 to 3 | 66.0% | 88.8% | Claude Sonnet 5.5 |
| FrontierMath, tier 4 | 26.8% | 80.5% | Claude Sonnet 5.5 |
| ProofBench | 50.0% | 100.0% | Claude Sonnet 5.5 |
| LMArena Text: math | 1518 | 1497 | Claude Opus 4.6 |
| LMArena Text: mathematical work | 1525 | 1510 | Claude Opus 4.6 |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index51
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| MMLU Pro | 89.1% | Not measured | Only Claude Opus 4.6 measured |
| LegalBench (Vals AI) | 85.3% | Not measured | Only Claude Opus 4.6 measured |
| CaseLaw (Vals AI) | 62.1% | Not measured | Only Claude Opus 4.6 measured |
| CorpFin (Vals AI) | 67.0% | Not measured | Only Claude Opus 4.6 measured |
| TaxEval (Vals AI) | 76.0% | Not measured | Only Claude Opus 4.6 measured |
| MortgageTax (Vals AI) | 68.5% | Not measured | Only Claude Opus 4.6 measured |
| MedQA (Vals AI) | 95.4% | Not measured | Only Claude Opus 4.6 measured |
| MedCode (Vals AI) | 49.1% | 52.9% | Claude Sonnet 5.5 |
| SimpleQA Verified | 47.0% | 46.5% | Claude Opus 4.6 |
| LMArena Text: science | 1519 | 1483 | Claude Opus 4.6 |
| LMArena Text: medicine and healthcare | 1504 | 1464 | Claude Opus 4.6 |
| LMArena Text: legal and government | 1512 | 1483 | Claude Opus 4.6 |
| LMArena Text: business and finance | 1497 | 1468 | Claude Opus 4.6 |
| FACTS Benchmark Suite | 41.5% | Not measured | Only Claude Opus 4.6 measured |
| 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 | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| Design Arena: websites | 1291 | 1327 | Claude Sonnet 5.5 |
| Design Arena: UI components | 1282 | 1369 | Claude Sonnet 5.5 |
| Design Arena: game dev | 1277 | 1472 | Claude Sonnet 5.5 |
| Design Arena: data viz | 1280 | 1382 | Claude Sonnet 5.5 |
| Design Arena: 3D | 1273 | 1442 | Claude Sonnet 5.5 |
| Design Arena: all code categories | 1288 | 1365 | Claude Sonnet 5.5 |
| Design Arena: SVG | 1227 | Not measured | Only Claude Opus 4.6 measured |
| Design Arena: ASCII art | 1255 | Not measured | Only Claude Opus 4.6 measured |
| LiveBench design | Not measured | 85.0% | Only Claude Sonnet 5.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index176
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | Leader |
|---|---|---|---|
| Vals Index | Not measured | 70.8% | Only Claude Sonnet 5.5 measured |
| LiveBench data analysis | Not measured | 59.5% | Only Claude Sonnet 5.5 measured |
| Public Benefits Bench (Vals AI) | Not measured | 67.2% | Only Claude Sonnet 5.5 measured |
| SAGE (Vals AI) | 51.6% | 51.8% | Claude Sonnet 5.5 |
| MedScribe (Vals AI) | 86.7% | 91.1% | Claude Sonnet 5.5 |
| IFBench | 53.1% | Not measured | Only Claude Opus 4.6 measured |
| Long context reasoning (AA-LCR) | 78.0% | 82.7% | Claude Sonnet 5.5 |
| DTBench | 91.2% | 97.3% | Claude Sonnet 5.5 |
| LMCA | 55.8% | 68.3% | Claude Sonnet 5.5 |
| CL-bench | 20.7% | Not measured | Only Claude Opus 4.6 measured |
| Furniture assembly | 28.3% | 75.0% | Claude Sonnet 5.5 |
| CL-bench Life | 17.0% | Not measured | Only Claude Opus 4.6 measured |
| LMArena Text | 1501 | 1473 | Claude Opus 4.6 |
| LMArena Text: instruction following | 1521 | 1492 | Claude Opus 4.6 |
| LMArena Text: creative writing | 1505 | 1467 | Claude Opus 4.6 |
| LMArena Vision | 1316 | 1287 | Claude Opus 4.6 |
| LMArena Text: English | 1511 | 1484 | Claude Opus 4.6 |
| LMArena Text: non-English | 1488 | 1456 | Claude Opus 4.6 |
| LMArena Text: Chinese | 1551 | 1535 | Claude Opus 4.6 |
| LMArena Text: German | 1500 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Text: Japanese | 1488 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Text: Korean | 1464 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Text: French | 1512 | 1499 | Claude Opus 4.6 |
| LMArena Text: Spanish | 1510 | 1451 | Claude Opus 4.6 |
| LMArena Text: Russian | 1497 | 1454 | Claude Opus 4.6 |
| LMArena Text: Polish | 1499 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Text: multi-turn | 1511 | 1465 | Claude Opus 4.6 |
| LMArena Text: longer queries | 1518 | 1495 | Claude Opus 4.6 |
| LMArena Text: writing and language | 1502 | 1474 | Claude Opus 4.6 |
| LMArena Text: entertainment and media | 1492 | 1461 | Claude Opus 4.6 |
| LMArena Vision: English | 1324 | 1289 | Claude Opus 4.6 |
| LMArena Vision: Chinese | 1370 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Vision: reading text | 1326 | 1297 | Claude Opus 4.6 |
| LMArena Vision: humor | 1314 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Vision: recognizing things | 1274 | Not measured | Only Claude Opus 4.6 measured |
| LMArena Vision: creative writing | 1331 | 1242 | Claude Opus 4.6 |
| LMArena Document | 1507 | Not measured | Only Claude Opus 4.6 measured |
| Neither model has a result on the other 9 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.6 | Claude Sonnet 5.5 | 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
Claude Opus 4.6$0.018Fits in one request
Claude Sonnet 5.5$0.0070Fits in one request
Claude Sonnet 5.5 costs less
Repository review
50K input + 3K output tokens
Claude Opus 4.6$0.325Fits in one request
Claude Sonnet 5.5$0.130Fits in one request
Claude Sonnet 5.5 costs less
Agent loop
200K input + 10K output tokens
Claude Opus 4.6$1.25Fits in one request
Claude Sonnet 5.5$0.500Fits in one request
Claude Sonnet 5.5 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 Opus 4.6 | Anthropic Claude Sonnet 5.5 |
|---|---|---|
| Maker | Anthropic | Anthropic |
| Weights | No public weights listed | No public weights listed |
| Released | February 4, 2026 | September 28, 2026 |
| Context window | 1M | 1M |
| Input $/Mtok | $5.00 | $2.00 |
| Output $/Mtok | $25.00 | $10.00 |
| Coding index | 57.2 | 87.3 |
| Independent measurements behind it | 4 | 5 |
| Cost per solved task | $1.56 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.6 better than Claude Sonnet 5.5 for coding?
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 57.2 for Claude Opus 4.6. Pick Claude Opus 4.6 for work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.
Which is cheaper, Claude Opus 4.6 or Claude Sonnet 5.5?
Claude Opus 4.6 costs $5.00 per million input tokens and $25.00 per million output tokens; Claude Sonnet 5.5 costs $2.00 and $10.00. Cost per solved task is known for Claude Opus 4.6 only.
Which has the bigger context window, Claude Opus 4.6 or Claude Sonnet 5.5?
Neither: both take 1M tokens.
How many benchmarks is the Claude Opus 4.6 vs Claude Sonnet 5.5 comparison based on?
64 benchmarks have a result for both models as of October 22, 2026. Claude Opus 4.6's coding index rests on 4 independent benchmarks and Claude Sonnet 5.5's on 5. Where only one model has a result, the page says so instead of naming a winner.