Claude Opus 5.5 vs Inkling
Claude Opus 5.5 leads Inkling on coding, 88.8 to 31.5 on the Vibe Coding Index, and Inkling costs 4.9x less per output token ($4.05 vs $20.00 per million). Updated October 21, 2026; 82 benchmarks have a result for both.
Claude Opus 5.5 or Inkling: which to pick
Pick Claude Opus 5.5 for coding: it scores 88.8 on the Vibe Coding Index against 31.5 for Inkling, though on 5 benchmarks against 6.
Pick Inkling for output tokens 4.9x cheaper ($4.05 vs $20.00 per million).
- Shared results
- 82
- Claude Opus 5.5 only
- 27
- Inkling only
- 20
- 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 31.5.
5 and 6 benchmarks behind the scores
Intelligence
AA Intelligence Index
Claude Opus 5.5
Claude Opus 5.5 leads, 57.6 against 25.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Inkling has a AA Agentic Index result, 22.5.
Directional only
Reasoning
GPQA Diamond
No call
Only Inkling has a GPQA Diamond result, 87.1%.
Directional only
Knowledge
MMLU Pro
No call
Only Inkling has a MMLU Pro result, 86.3%.
Directional only
Web design
Design Arena: websites
Claude Opus 5.5
Claude Opus 5.5 leads, 1336 against 1224.
Same board, both measured
General
Vals Index
Claude Opus 5.5
Claude Opus 5.5 leads, 70.2% against 29.0%.
Same board, both measured
Long documents
Listed context window
Claude Opus 5.5
Claude Opus 5.5 takes 1M tokens against 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Inkling
Claude Opus 5.5 $0.014, Inkling $0.0030 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Inkling has the number, $0.76.
Directional only
At a glance
- Coding index
- Claude Opus 5.5 88.8 from 5 benchmarks, Inkling 31.5 from 6 benchmarks.
- Widest category
- Math, 45.8 points apart on average over 6 shared benchmarks.
- Widest single gap
- ProofBench: Claude Opus 5.5 100.0% against Inkling 0.0%, 100.0 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 5.5 $20.00 against Inkling $4.05 per million output tokens, 4.9x apart.
- Context window
- Claude Opus 5.5 takes 1M tokens, Inkling 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 | Claude Opus 5.5 | Bars | Inkling | Ties |
|---|---|---|---|---|
| Coding | 18 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 11 | 0 | ||
| Reasoning | 9 | 0 | ||
| Math | 6 | 0 | ||
| Knowledge | 6 | 0 | ||
| Web design | 8 | 0 | ||
| General | 22 | 0 | ||
| All shared boards | 82 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index180
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| LiveBench coding | 96.3% | 64.0% | Claude Opus 5.5 |
| LMArena WebDev | 1807 | 1414 | Claude Opus 5.5 |
| AA Coding Index | Not measured | 52.1 | Only Inkling measured |
| LiveCodeBench (Vals AI) | Not measured | 85.5% | Only Inkling measured |
| SWE-bench Verified (Vals AI) | Not measured | 77.6% | Only Inkling measured |
| Terminal-Bench 4 (Vals AI) | 65.2% | 0.5% | Claude Opus 5.5 |
| Vibe Code Bench (Vals AI) | 90.3% | 19.2% | Claude Opus 5.5 |
| Code migration (Vals AI) | 66.7% | 11.8% | Claude Opus 5.5 |
| ProgramBench (Vals AI) | 18.5% | 0.0% | Claude Opus 5.5 |
| IOI (Vals AI) | 95.1% | 14.9% | Claude Opus 5.5 |
| Terminal-Bench 2.1 (Vals AI) | 87.6% | 47.6% | Claude Opus 5.5 |
| SWE-bench Multimodal (Vals AI) | 70.2% | Not measured | Only Claude Opus 5.5 measured |
| Vibe Code Bench 1-100 (Vals AI) | 30.4% | 7.3% | Claude Opus 5.5 |
| SkillsBench (Vals AI) | Not measured | 26.1% | Only Inkling measured |
| CyberBench (Vals AI) | 74.6% | 66.8% | Claude Opus 5.5 |
| SciCode | 66.9% | 47.0% | Claude Opus 5.5 |
| FrontierCode | 54.6% | 14.0% | Claude Opus 5.5 |
| FrontierSWE | 62.3% | 4.1% | Claude Opus 5.5 |
| WeirdML | Not measured | 32.3% | Only Inkling measured |
| MirrorCode | 77.4% | Not measured | Only Claude Opus 5.5 measured |
| ALE-Bench | 2147.4 | 946.0 | Claude Opus 5.5 |
| LMArena Text: coding | 1545 | 1466 | Claude Opus 5.5 |
| LMArena Text: software and IT | 1538 | 1465 | Claude Opus 5.5 |
| LMArena WebDev: React | 1855 | 1404 | Claude Opus 5.5 |
| LMArena WebDev: HTML | 1753 | 1399 | 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 12 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| AA Intelligence Index | 57.6 | 25.0 | Claude Opus 5.5 |
| Epoch Capabilities Index | 168.8 | 148.4 | Claude Opus 5.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index110
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 22.5 | Only Inkling measured |
| Design Arena: agents building web apps | 1317 | 1196 | Claude Opus 5.5 |
| Design Arena: agents building mobile apps | 1310 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: spreadsheets | 1352 | Not measured | Only Claude Opus 5.5 measured |
| LiveBench research | 85.0% | 59.9% | Claude Opus 5.5 |
| LiveBench browser | 80.0% | 16.0% | Claude Opus 5.5 |
| LiveBench long agentic | 85.0% | 14.1% | Claude Opus 5.5 |
| SREBench (Vals AI) | 33.6% | 0.0% | Claude Opus 5.5 |
| Finance Agent (Vals AI) | 58.6% | 46.6% | Claude Opus 5.5 |
| Tax Agent Bench (Vals AI) | 45.6% | 15.3% | Claude Opus 5.5 |
| Legal Research Bench (Vals AI) | 50.5% | 28.4% | Claude Opus 5.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 9.2% | 3.8% | Claude Opus 5.5 |
| Excel Modeling Benchmark (Vals AI) | 75.9% | 38.4% | Claude Opus 5.5 |
| BioMysteryBench (Vals AI) | 79.3% | Not measured | Only Claude Opus 5.5 measured |
| 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% | 33.8% | Claude Opus 5.5 |
| 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 17 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index90
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 87.1% | Only Inkling measured |
| LiveBench reasoning | 92.2% | 78.3% | Claude Opus 5.5 |
| MysteryMechanism (Vals AI) | 49.5% | Not measured | Only Claude Opus 5.5 measured |
| MMMU Pro (Vals AI) | Not measured | 78.5% | Only Inkling measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 87.2% | Only Inkling measured |
| Humanity's Last Exam (Artificial Analysis run) | 61.4% | 31.9% | Claude Opus 5.5 |
| GPQA Diamond (Epoch AI run) | 90.6% | 88.3% | Claude Opus 5.5 |
| ARC-AGI | 98.5% | 79.5% | Claude Opus 5.5 |
| ARC-AGI-2 | 93.3% | 36.5% | Claude Opus 5.5 |
| SimpleBench | Not measured | 50.0% | Only Inkling measured |
| Chess puzzles | 67.0% | 21.0% | Claude Opus 5.5 |
| Mystery game puzzles | 71.0% | Not measured | Only Claude Opus 5.5 measured |
| EBR-bench | 71.4% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: hard prompts | 1536 | 1451 | Claude Opus 5.5 |
| LMArena Text: expert | 1549 | 1466 | Claude Opus 5.5 |
| LMArena Text: hard prompts in English | 1535 | 1448 | Claude Opus 5.5 |
| LMArena Vision: diagrams | 1345 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: homework | 1362 | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | 88.9% | Claude Opus 5.5 |
| FrontierMath, tiers 1 to 3 | 91.2% | 33.3% | Claude Opus 5.5 |
| FrontierMath, tier 4 | 95.0% | 4.9% | Claude Opus 5.5 |
| ProofBench | 100.0% | 0.0% | Claude Opus 5.5 |
| LMArena Text: math | 1518 | 1479 | Claude Opus 5.5 |
| LMArena Text: mathematical work | 1516 | 1460 | 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 | Inkling | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 86.3% | Only Inkling measured |
| LegalBench (Vals AI) | Not measured | 83.0% | Only Inkling measured |
| CorpFin (Vals AI) | Not measured | 68.6% | Only Inkling measured |
| TaxEval (Vals AI) | Not measured | 75.3% | Only Inkling measured |
| MortgageTax (Vals AI) | Not measured | 64.0% | Only Inkling measured |
| MedCode (Vals AI) | 49.8% | 41.2% | Claude Opus 5.5 |
| SimpleQA Verified | 72.2% | 40.3% | Claude Opus 5.5 |
| LMArena Text: science | 1524 | 1455 | Claude Opus 5.5 |
| LMArena Text: medicine and healthcare | 1509 | 1447 | Claude Opus 5.5 |
| LMArena Text: legal and government | 1518 | 1448 | Claude Opus 5.5 |
| LMArena Text: business and finance | 1494 | 1438 | 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 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| Design Arena: websites | 1336 | 1224 | Claude Opus 5.5 |
| Design Arena: UI components | 1392 | 1201 | Claude Opus 5.5 |
| Design Arena: game dev | 1458 | 1166 | Claude Opus 5.5 |
| Design Arena: data viz | 1397 | 1159 | Claude Opus 5.5 |
| Design Arena: 3D | 1477 | 1161 | Claude Opus 5.5 |
| Design Arena: all code categories | 1390 | 1206 | Claude Opus 5.5 |
| Design Arena: SVG | 1333 | 1110 | Claude Opus 5.5 |
| Design Arena: ASCII art | Not measured | 1089 | Only Inkling measured |
| LiveBench design | 86.9% | 58.3% | Claude Opus 5.5 |
GeneralLike-for-likePublic boards, shown as published, kept out of the index220
| Benchmark | Claude Opus 5.5 | Inkling | Leader |
|---|---|---|---|
| Vals Index | 70.2% | 29.0% | Claude Opus 5.5 |
| LiveBench data analysis | 80.3% | 72.8% | Claude Opus 5.5 |
| Public Benefits Bench (Vals AI) | 70.6% | 58.5% | Claude Opus 5.5 |
| SAGE (Vals AI) | 45.8% | 36.5% | Claude Opus 5.5 |
| MedScribe (Vals AI) | 91.4% | 85.4% | Claude Opus 5.5 |
| Vals Multimodal Index | Not measured | 49.4% | Only Inkling measured |
| Long context reasoning (AA-LCR) | 84.7% | 77.3% | Claude Opus 5.5 |
| DTBench | 98.9% | 87.5% | Claude Opus 5.5 |
| LMCA | 68.2% | 37.6% | Claude Opus 5.5 |
| Furniture assembly | 83.3% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text | 1516 | 1442 | Claude Opus 5.5 |
| LMArena Text: instruction following | 1537 | 1425 | Claude Opus 5.5 |
| LMArena Text: creative writing | 1535 | 1390 | Claude Opus 5.5 |
| LMArena Vision | 1321 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: English | 1519 | 1442 | Claude Opus 5.5 |
| LMArena Text: non-English | 1507 | 1434 | Claude Opus 5.5 |
| LMArena Text: Chinese | 1582 | 1493 | Claude Opus 5.5 |
| LMArena Text: German | Not measured | 1445 | Only Inkling measured |
| LMArena Text: Japanese | 1534 | 1429 | Claude Opus 5.5 |
| LMArena Text: Korean | Not measured | 1403 | Only Inkling measured |
| LMArena Text: French | 1493 | 1455 | Claude Opus 5.5 |
| LMArena Text: Spanish | 1508 | 1449 | Claude Opus 5.5 |
| LMArena Text: Russian | 1517 | 1430 | Claude Opus 5.5 |
| LMArena Text: Polish | Not measured | 1450 | Only Inkling measured |
| LMArena Text: multi-turn | 1501 | 1437 | Claude Opus 5.5 |
| LMArena Text: longer queries | 1532 | 1435 | Claude Opus 5.5 |
| LMArena Text: writing and language | 1532 | 1404 | Claude Opus 5.5 |
| LMArena Text: entertainment and media | 1515 | 1394 | Claude Opus 5.5 |
| LMArena Vision: English | 1317 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: reading text | 1326 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: creative writing | 1320 | Not measured | Only Claude Opus 5.5 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 | Claude Opus 5.5 | Inkling | 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
Inkling costs less
Repository review
50K input + 3K output tokens
Inkling costs less
Agent loop
200K input + 10K output tokens
Inkling 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 | Thinking Machines Inkling |
|---|---|---|
| Maker | Anthropic | Thinking Machines |
| Weights | No public weights listed | Open weights |
| Released | September 22, 2026 | July 17, 2026 |
| Context window | 1M | 524K |
| Input $/Mtok | $4.00 | $0.975 |
| Output $/Mtok | $20.00 | $4.05 |
| Coding index | 88.8 | 31.5 |
| Independent measurements behind it | 5 | 6 |
| Cost per solved task | Not computable | $0.76 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 5.5 better than Inkling for coding?
Pick Claude Opus 5.5 for coding: it scores 88.8 on the Vibe Coding Index against 31.5 for Inkling, though on 5 benchmarks against 6. Pick Inkling for output tokens 4.9x cheaper ($4.05 vs $20.00 per million).
Which is cheaper, Claude Opus 5.5 or Inkling?
Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; Inkling costs $0.975 and $4.05. Cost per solved task is known for Inkling only.
Which has the bigger context window, Claude Opus 5.5 or Inkling?
Claude Opus 5.5, with 1M tokens against 524K.
How many benchmarks is the Claude Opus 5.5 vs Inkling comparison based on?
82 benchmarks have a result for both models as of October 21, 2026. Claude Opus 5.5's coding index rests on 5 independent benchmarks and Inkling's on 6. Where only one model has a result, the page says so instead of naming a winner.