Claude Opus 4.5 vs Inkling 2 Small
Inkling 2 Small leads Claude Opus 4.5 on coding, 48.9 to 43.9 on the Vibe Coding Index, and Inkling 2 Small costs 25.0x less per output token ($1.00 vs $25.00 per million). Updated November 14, 2026; 26 benchmarks have a result for both.
vs boards won of 26 shared
Claude Opus 4.5 or Inkling 2 Small: which to pick
Pick Inkling 2 Small for coding: it scores 48.9 on the Vibe Coding Index against 43.9 for Claude Opus 4.5.
Pick Claude Opus 4.5 for work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.
Model AClaude Opus 4.5Anthropic43.9/1003 independent benchmarks$1.37 per solved taskModel BInkling 2 SmallThinking Machines48.9/1003 independent benchmarksNo cost per solved task
- Shared results
- 26
- Claude Opus 4.5 only
- 86
- Inkling 2 Small only
- 25
- Like-for-like categories
- 5 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
Inkling 2 Small
Inkling 2 Small scores 48.9 against 43.9.
3 benchmarks behind each score
Intelligence
AA Intelligence Index
No call
Only Inkling 2 Small has a AA Intelligence Index result, 30.6.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.5 has a GPQA Diamond result, 85.9%.
Directional only
Math
AIME
No call
Only Claude Opus 4.5 has a AIME result, 95.4%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Opus 4.5 has a MMLU Pro result, 87.3%.
Directional only
Web design
Design Arena: websites
No call
Only Claude Opus 4.5 has a Design Arena: websites result, 1239.
Directional only
General
Vals Index
No call
Only Inkling 2 Small has a Vals Index result, 56.1%.
Directional only
Long documents
Listed context window
Inkling 2 Small
Inkling 2 Small takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Inkling 2 Small
Claude Opus 4.5 $0.018, Inkling 2 Small $0.0008 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Opus 4.5 has the number, $1.37.
Directional only
At a glance
- Coding index
- Claude Opus 4.5 43.9 from 3 benchmarks, Inkling 2 Small 48.9 from 3 benchmarks.
- Widest category
- Coding, 22.2 points apart on average over 6 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Claude Opus 4.5 20.6% against Inkling 2 Small 81.5%, 60.9 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.5 $25.00 against Inkling 2 Small $1.00 per million output tokens, 25.0x apart.
- Context window
- Claude Opus 4.5 takes 200K tokens, Inkling 2 Small 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 4.5 | Bars | Inkling 2 Small | Ties |
|---|---|---|---|---|
| Coding | 2 | 4 | ||
| Agentic work | 0 | 1 | ||
| Reasoning | 3 | 3 | ||
| Knowledge | 2 | 0 | ||
| General | 10 | 1 | ||
| All shared boards | 17 | 9 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index24
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| SWE-bench Verified | 79.2% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench (full test set) | 52.6% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench Multilingual | 70.7% | Not measured | Only Claude Opus 4.5 measured |
| LMArena WebDev | 1493 | 1647 | Inkling 2 Small |
| LiveCodeBench (Vals AI) | 83.7% | Not measured | Only Claude Opus 4.5 measured |
| SWE-bench Verified (Vals AI) | 76.4% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 12.6% | Only Inkling 2 Small measured |
| Vibe Code Bench (Vals AI) | 20.6% | 81.5% | Inkling 2 Small |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Inkling 2 Small measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 43.1% | Only Inkling 2 Small measured |
| CyberBench (Vals AI) | Not measured | 72.7% | Only Inkling 2 Small measured |
| LiveCodeBench (Artificial Analysis run) | 87.1% | Not measured | Only Claude Opus 4.5 measured |
| SciCode | Not measured | 52.3% | Only Inkling 2 Small measured |
| Terminal-Bench Hard (Artificial Analysis run) | 47.0% | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | Not measured | 13.1% | Only Inkling 2 Small measured |
| FrontierCode 2.0 | Not measured | 25.4% | Only Inkling 2 Small measured |
| Terminal-Bench | 63.1% | Not measured | Only Claude Opus 4.5 measured |
| GSO-Bench | 26.5% | Not measured | Only Claude Opus 4.5 measured |
| WeirdML | 63.7% | Not measured | Only Claude Opus 4.5 measured |
| Cybench | 82.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: coding | 1503 | 1455 | Claude Opus 4.5 |
| LMArena Text: software and IT | 1483 | 1443 | Claude Opus 4.5 |
| LMArena WebDev: React | 1477 | 1660 | Inkling 2 Small |
| LMArena WebDev: HTML | 1511 | 1661 | Inkling 2 Small |
| SWE-Bench Pro V2 | Not measured | 97.7% | Only Inkling 2 Small measured |
| GameBench 2 | 49.9 | Not measured | Only Claude Opus 4.5 measured |
| Terminal-Bench 2.0 | 63.1% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 25 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 30.6 | Only Inkling 2 Small measured |
| Epoch Capabilities Index | 151.9 | Not measured | Only Claude Opus 4.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1135 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building full-stack apps | 1130 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building mobile apps | 1181 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: agents building Android apps | 1162 | Not measured | Only Claude Opus 4.5 measured |
| SREBench (Vals AI) | Not measured | 1.9% | Only Inkling 2 Small measured |
| Tax Agent Bench (Vals AI) | Not measured | 38.9% | Only Inkling 2 Small measured |
| Legal Research Bench (Vals AI) | Not measured | 46.6% | Only Inkling 2 Small measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 21.7% | Only Inkling 2 Small measured |
| BioMysteryBench (Vals AI) | Not measured | 70.0% | Only Inkling 2 Small measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 2.9% | Only Inkling 2 Small measured |
| Vals Science Index | Not measured | 32.7% | Only Inkling 2 Small measured |
| τ²-Bench Telecom | 89.5% | Not measured | Only Claude Opus 4.5 measured |
| APEX-Agents | Not measured | 46.8% | Only Inkling 2 Small measured |
| METR time horizons | 75.0% | Not measured | Only Claude Opus 4.5 measured |
| Remote Labor Index | 3.8% | Not measured | Only Claude Opus 4.5 measured |
| GDPval | 45.5% | Not measured | Only Claude Opus 4.5 measured |
| BALROG | 43.5% | Not measured | Only Claude Opus 4.5 measured |
| DeepResearch Bench | 54.8% | Not measured | Only Claude Opus 4.5 measured |
| OSWorld | 66.3% | Not measured | Only Claude Opus 4.5 measured |
| Vending-Bench 2 | $4,967 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Search | 1179 | Not measured | Only Claude Opus 4.5 measured |
| Berkeley Function Calling Leaderboard (BFCL) | 77.5% | Not measured | Only Claude Opus 4.5 measured |
| MCP Atlas | 69.8% | 85.4% | Inkling 2 Small |
| τ³-Banking | 24.7% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 20 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index33
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| GPQA Diamond | 85.9% | Not measured | Only Claude Opus 4.5 measured |
| MysteryMechanism (Vals AI) | Not measured | 25.2% | Only Inkling 2 Small measured |
| MMMU Pro (Vals AI) | 83.0% | Not measured | Only Claude Opus 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | 86.6% | Not measured | Only Claude Opus 4.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 30.1% | 44.1% | Inkling 2 Small |
| HLE-Diamond (Artificial Analysis run) | Not measured | 28.7% | Only Inkling 2 Small measured |
| CritPt v2, hard subset (Artificial Analysis run) | Not measured | 35.0% | Only Inkling 2 Small measured |
| GPQA Diamond (Epoch AI run) | 86.0% | Not measured | Only Claude Opus 4.5 measured |
| ARC-AGI | 80.0% | 96.5% | Inkling 2 Small |
| ARC-AGI-2 | 37.6% | 81.7% | Inkling 2 Small |
| SimpleBench | 62.0% | Not measured | Only Claude Opus 4.5 measured |
| Chess puzzles | 14.0% | Not measured | Only Claude Opus 4.5 measured |
| Mystery game puzzles | 22.0% | Not measured | Only Claude Opus 4.5 measured |
| EBR-bench | 14.3% | Not measured | Only Claude Opus 4.5 measured |
| VPCT | 40.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: hard prompts | 1477 | 1421 | Claude Opus 4.5 |
| LMArena Text: expert | 1488 | 1478 | Claude Opus 4.5 |
| LMArena Text: hard prompts in English | 1482 | 1424 | Claude Opus 4.5 |
| Kagi LLM Benchmark | 80.2% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 7 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| AIME | 95.4% | Not measured | Only Claude Opus 4.5 measured |
| MGSM (Vals AI) | 95.2% | Not measured | Only Claude Opus 4.5 measured |
| AIME 2025 (Artificial Analysis run) | 91.3% | Not measured | Only Claude Opus 4.5 measured |
| OTIS Mock AIME | 86.1% | Not measured | Only Claude Opus 4.5 measured |
| FrontierMath, tiers 1 to 3 | 34.4% | Not measured | Only Claude Opus 4.5 measured |
| FrontierMath, tier 4 | 4.9% | Not measured | Only Claude Opus 4.5 measured |
| ProofBench | 36.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: math | 1463 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: mathematical work | 1468 | Not measured | Only Claude Opus 4.5 measured |
| MathArena | Not measured | 42.4% | Only Inkling 2 Small measured |
| Neither model has a result on the other 4 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| MMLU Pro | 87.3% | Not measured | Only Claude Opus 4.5 measured |
| LegalBench (Vals AI) | 84.6% | Not measured | Only Claude Opus 4.5 measured |
| CaseLaw (Vals AI) | 62.6% | Not measured | Only Claude Opus 4.5 measured |
| CorpFin (Vals AI) | 65.1% | Not measured | Only Claude Opus 4.5 measured |
| TaxEval (Vals AI) | 74.9% | Not measured | Only Claude Opus 4.5 measured |
| MortgageTax (Vals AI) | 68.7% | Not measured | Only Claude Opus 4.5 measured |
| MedQA (Vals AI) | 95.9% | Not measured | Only Claude Opus 4.5 measured |
| MedCode (Vals AI) | 49.2% | Not measured | Only Claude Opus 4.5 measured |
| MMLU Pro (Artificial Analysis run) | 89.5% | Not measured | Only Claude Opus 4.5 measured |
| AA-Omniscience | Not measured | 16.1 | Only Inkling 2 Small measured |
| SimpleQA Verified | 45.7% | Not measured | Only Claude Opus 4.5 measured |
| GeoBench | 75.0% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: science | 1453 | 1409 | Claude Opus 4.5 |
| LMArena Text: medicine and healthcare | 1444 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: legal and government | 1459 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: business and finance | 1449 | 1415 | Claude Opus 4.5 |
| PRBench Finance | 46.2% | Not measured | Only Claude Opus 4.5 measured |
| PRBench Legal | 44.2% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 3 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| Design Arena: websites | 1239 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: UI components | 1228 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: game dev | 1218 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: data viz | 1240 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: 3D | 1193 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: all code categories | 1231 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: SVG | 1170 | Not measured | Only Claude Opus 4.5 measured |
| Design Arena: ASCII art | 1185 | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index101
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | Leader |
|---|---|---|---|
| Vals Index | Not measured | 56.1% | Only Inkling 2 Small measured |
| SAGE (Vals AI) | Not measured | 88.6% | Only Inkling 2 Small measured |
| MedScribe (Vals AI) | 85.3% | Not measured | Only Claude Opus 4.5 measured |
| IFBench | 58.0% | Not measured | Only Claude Opus 4.5 measured |
| Long context reasoning (AA-LCR) | 77.3% | 83.3% | Inkling 2 Small |
| GDPval-AA | Not measured | 1630 | Only Inkling 2 Small measured |
| DTBench | 89.9% | Not measured | Only Claude Opus 4.5 measured |
| LMCA | 44.5% | Not measured | Only Claude Opus 4.5 measured |
| CL-bench | 21.1% | Not measured | Only Claude Opus 4.5 measured |
| Furniture assembly | 28.3% | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text | 1451 | 1403 | Claude Opus 4.5 |
| LMArena Text: instruction following | 1478 | 1408 | Claude Opus 4.5 |
| LMArena Text: creative writing | 1444 | 1348 | Claude Opus 4.5 |
| LMArena Text: English | 1461 | 1418 | Claude Opus 4.5 |
| LMArena Text: non-English | 1437 | 1390 | Claude Opus 4.5 |
| LMArena Text: Chinese | 1470 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: German | 1449 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Japanese | 1417 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Korean | 1425 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: French | 1470 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Spanish | 1458 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: Russian | 1447 | 1377 | Claude Opus 4.5 |
| LMArena Text: Polish | 1439 | Not measured | Only Claude Opus 4.5 measured |
| LMArena Text: multi-turn | 1466 | 1408 | Claude Opus 4.5 |
| LMArena Text: longer queries | 1479 | 1403 | Claude Opus 4.5 |
| LMArena Text: writing and language | 1451 | 1381 | Claude Opus 4.5 |
| LMArena Text: entertainment and media | 1434 | 1359 | Claude Opus 4.5 |
| LMArena Document | 1466 | Not measured | Only Claude Opus 4.5 measured |
| MultiChallenge | 59.0% | Not measured | Only Claude Opus 4.5 measured |
| Neither model has a result on the other 20 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.5 | Inkling 2 Small | 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 4.5$0.018Fits in one request
Inkling 2 Small$0.0008Fits in one request
Inkling 2 Small costs less
Repository review
50K input + 3K output tokens
Claude Opus 4.5$0.325Fits in one request
Inkling 2 Small$0.018Fits in one request
Inkling 2 Small costs less
Agent loop
200K input + 10K output tokens
Claude Opus 4.5$1.25Exceeds the context window
Inkling 2 Small$0.070Fits in one request
Inkling 2 Small 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 4.5 | Thinking Machines Inkling 2 Small |
|---|---|---|
| Maker | Anthropic | Thinking Machines |
| Weights | No public weights listed | Open weights |
| Released | November 24, 2025 | November 9, 2026 |
| Context window | 200K | 1.05M |
| Input $/Mtok | $5.00 | $0.30 |
| Output $/Mtok | $25.00 | $1.00 |
| Coding index | 43.9 | 48.9 |
| Independent measurements behind it | 3 | 3 |
| Cost per solved task | $1.37 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.5 better than Inkling 2 Small for coding?
Pick Inkling 2 Small for coding: it scores 48.9 on the Vibe Coding Index against 43.9 for Claude Opus 4.5. Pick Claude Opus 4.5 for work measured by LMArena Text: coding or LMArena Text: software and IT, where it leads.
Which is cheaper, Claude Opus 4.5 or Inkling 2 Small?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Inkling 2 Small costs $0.30 and $1.00. Cost per solved task is known for Claude Opus 4.5 only.
Which has the bigger context window, Claude Opus 4.5 or Inkling 2 Small?
Inkling 2 Small, with 1.05M tokens against 200K.
How many benchmarks is the Claude Opus 4.5 vs Inkling 2 Small comparison based on?
26 benchmarks have a result for both models as of November 14, 2026. Claude Opus 4.5's coding index rests on 3 independent benchmarks and Inkling 2 Small's on 3. Where only one model has a result, the page says so instead of naming a winner.