Inkling Small vs Solar Pro 4
Solar Pro 4 leads Inkling Small on the Artificial Analysis Intelligence Index, 28.2 to 25.7, and Solar Pro 4 costs 2.0x less per output token ($0.60 vs $1.20 per million). Updated October 22, 2026; 37 benchmarks have a result for both.
Inkling Small or Solar Pro 4: which to pick
Only Inkling Small has a coding score, 27.3 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding.
Pick Solar Pro 4 for output tokens 2.0x cheaper ($0.60 vs $1.20 per million) and work measured by AA Intelligence Index or LMArena Text: Korean, where it leads.
- Shared results
- 37
- Inkling Small only
- 47
- Solar Pro 4 only
- 8
- Like-for-like categories
- 6 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
No call
Only Inkling Small has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Solar Pro 4
Solar Pro 4 leads, 28.2 against 25.7.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Inkling Small has a AA Agentic Index result, 23.5.
Directional only
Reasoning
GPQA Diamond
No call
Only Inkling Small has a GPQA Diamond result, 83.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Inkling Small has a MMLU Pro result, 85.6%.
Directional only
Web design
Design Arena: websites
No call
Only Solar Pro 4 has a Design Arena: websites result, 1176.
Directional only
General
Vals Index
No call
Only Inkling Small has a Vals Index result, 27.6%.
Directional only
Long documents
Listed context window
No call
Both take 524K tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Solar Pro 4
Inkling Small $0.0010, Solar Pro 4 $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Inkling Small has the number, $0.16.
Directional only
At a glance
- Coding index
- Inkling Small 27.3 from 4 benchmarks, Solar Pro 4 not benchmarked.
- Widest category
- General, 5.8 points apart on average over 18 shared benchmarks.
- Widest single gap
- LMArena Text: Polish: Inkling Small 1428 against Solar Pro 4 1304, 20.5 points apart on a 0 to 100 scale.
- Output price
- Inkling Small $1.20 against Solar Pro 4 $0.60 per million output tokens, 2.0x apart.
- Context window
- Both take 524K 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 | Inkling Small | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 5 | 0 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| General | 17 | 1 | ||
| All shared boards | 35 | 2 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| LMArena WebDev | 1409 | 1371 | Inkling Small |
| AA Coding Index | 52.9 | 52.7 | Inkling Small |
| LiveCodeBench (Vals AI) | 85.9% | Not measured | Only Inkling Small measured |
| SWE-bench Verified (Vals AI) | 82.2% | Not measured | Only Inkling Small measured |
| Terminal-Bench 4 (Vals AI) | 0.0% | Not measured | Only Inkling Small measured |
| Vibe Code Bench (Vals AI) | 19.1% | Not measured | Only Inkling Small measured |
| Code migration (Vals AI) | 13.7% | Not measured | Only Inkling Small measured |
| ProgramBench (Vals AI) | 0.5% | Not measured | Only Inkling Small measured |
| IOI (Vals AI) | 9.3% | Not measured | Only Inkling Small measured |
| Terminal-Bench 2.1 (Vals AI) | 55.1% | Not measured | Only Inkling Small measured |
| SkillsBench (Vals AI) | 33.6% | Not measured | Only Inkling Small measured |
| CyberBench (Vals AI) | 64.1% | Not measured | Only Inkling Small measured |
| SciCode | 49.7% | 48.0% | Inkling Small |
| ALE-Bench | Not measured | 179.3 | Only Solar Pro 4 measured |
| LMArena Text: coding | 1450 | 1438 | Inkling Small |
| LMArena Text: software and IT | 1447 | 1431 | Inkling Small |
| LMArena WebDev: React | 1399 | 1363 | Inkling Small |
| LMArena WebDev: HTML | 1398 | 1371 | Inkling Small |
| LMArena WebDev: from an image | 1410 | Not measured | Only Inkling Small measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 25.7 | 28.2 | Solar Pro 4 |
| Epoch Capabilities Index | 150.3 | Not measured | Only Inkling Small measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Agentic Index | 23.5 | Not measured | Only Inkling Small measured |
| Design Arena: agents building web apps | Not measured | 1105 | Only Solar Pro 4 measured |
| Finance Agent (Vals AI) | 41.3% | Not measured | Only Inkling Small measured |
| Tax Agent Bench (Vals AI) | 15.4% | Not measured | Only Inkling Small measured |
| Legal Research Bench (Vals AI) | 25.5% | Not measured | Only Inkling Small measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 2.9% | Not measured | Only Inkling Small measured |
| Excel Modeling Benchmark (Vals AI) | 31.8% | Not measured | Only Inkling Small measured |
| Neither model has a result on the other 34 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| GPQA Diamond | 83.6% | Not measured | Only Inkling Small measured |
| GPQA Diamond (Artificial Analysis run) | 89.5% | 89.1% | Inkling Small |
| Humanity's Last Exam (Artificial Analysis run) | 33.3% | 29.8% | Inkling Small |
| GPQA Diamond (Epoch AI run) | 88.5% | Not measured | Only Inkling Small measured |
| ARC-AGI | 84.0% | Not measured | Only Inkling Small measured |
| ARC-AGI-2 | 40.1% | Not measured | Only Inkling Small measured |
| Mystery game puzzles | 6.0% | Not measured | Only Inkling Small measured |
| LMArena Text: hard prompts | 1423 | 1400 | Inkling Small |
| LMArena Text: expert | 1441 | 1428 | Inkling Small |
| LMArena Text: hard prompts in English | 1429 | 1427 | Inkling Small |
| LMArena Vision: diagrams | 1251 | Not measured | Only Inkling Small measured |
| LMArena Vision: homework | 1257 | Not measured | Only Inkling Small measured |
| Neither model has a result on the other 10 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 90.0% | Not measured | Only Inkling Small measured |
| FrontierMath, tiers 1 to 3 | 46.3% | Not measured | Only Inkling Small measured |
| FrontierMath, tier 4 | 17.1% | Not measured | Only Inkling Small measured |
| ProofBench | 6.0% | Not measured | Only Inkling Small measured |
| LMArena Text: math | 1459 | 1421 | Inkling Small |
| LMArena Text: mathematical work | 1441 | 1427 | Inkling Small |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 85.6% | Not measured | Only Inkling Small measured |
| LegalBench (Vals AI) | 83.0% | Not measured | Only Inkling Small measured |
| CorpFin (Vals AI) | 69.6% | Not measured | Only Inkling Small measured |
| TaxEval (Vals AI) | 75.5% | Not measured | Only Inkling Small measured |
| MortgageTax (Vals AI) | 62.3% | Not measured | Only Inkling Small measured |
| MedCode (Vals AI) | 37.9% | Not measured | Only Inkling Small measured |
| SimpleQA Verified | 19.1% | Not measured | Only Inkling Small measured |
| LMArena Text: science | 1428 | 1404 | Inkling Small |
| LMArena Text: medicine and healthcare | 1413 | 1374 | Inkling Small |
| LMArena Text: legal and government | 1415 | 1383 | Inkling Small |
| LMArena Text: business and finance | 1413 | 1381 | Inkling Small |
| Neither model has a result on the other 7 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1176 | Only Solar Pro 4 measured |
| Design Arena: UI components | Not measured | 1147 | Only Solar Pro 4 measured |
| Design Arena: game dev | Not measured | 1169 | Only Solar Pro 4 measured |
| Design Arena: data viz | Not measured | 1177 | Only Solar Pro 4 measured |
| Design Arena: 3D | Not measured | 1178 | Only Solar Pro 4 measured |
| Design Arena: all code categories | Not measured | 1182 | Only Solar Pro 4 measured |
| Neither model has a result on the other 3 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index171
| Benchmark | Inkling Small | Solar Pro 4 | Leader |
|---|---|---|---|
| Vals Index | 27.6% | Not measured | Only Inkling Small measured |
| Public Benefits Bench (Vals AI) | 59.4% | Not measured | Only Inkling Small measured |
| SAGE (Vals AI) | 32.7% | Not measured | Only Inkling Small measured |
| MedScribe (Vals AI) | 84.1% | Not measured | Only Inkling Small measured |
| Vals Multimodal Index | 50.0% | Not measured | Only Inkling Small measured |
| Long context reasoning (AA-LCR) | 75.7% | 70.7% | Inkling Small |
| LMArena Text | 1413 | 1388 | Inkling Small |
| LMArena Text: instruction following | 1399 | 1375 | Inkling Small |
| LMArena Text: creative writing | 1334 | 1317 | Inkling Small |
| LMArena Vision | 1237 | Not measured | Only Inkling Small measured |
| LMArena Text: English | 1421 | 1414 | Inkling Small |
| LMArena Text: non-English | 1401 | 1363 | Inkling Small |
| LMArena Text: Chinese | 1464 | 1422 | Inkling Small |
| LMArena Text: German | 1408 | 1358 | Inkling Small |
| LMArena Text: Japanese | 1401 | 1320 | Inkling Small |
| LMArena Text: Korean | 1367 | 1383 | Solar Pro 4 |
| LMArena Text: French | 1435 | 1400 | Inkling Small |
| LMArena Text: Spanish | 1422 | 1409 | Inkling Small |
| LMArena Text: Russian | 1394 | 1357 | Inkling Small |
| LMArena Text: Polish | 1428 | 1304 | Inkling Small |
| LMArena Text: multi-turn | 1416 | 1385 | Inkling Small |
| LMArena Text: longer queries | 1402 | 1382 | Inkling Small |
| LMArena Text: writing and language | 1357 | 1344 | Inkling Small |
| LMArena Text: entertainment and media | 1352 | 1332 | Inkling Small |
| LMArena Vision: English | 1243 | Not measured | Only Inkling Small measured |
| LMArena Vision: Chinese | 1292 | Not measured | Only Inkling Small measured |
| LMArena Vision: reading text | 1243 | Not measured | Only Inkling Small measured |
| LMArena Vision: humor | 1207 | Not measured | Only Inkling Small measured |
| LMArena Vision: creative writing | 1205 | Not measured | Only Inkling Small measured |
| Neither model has a result on the other 17 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Inkling Small | Solar Pro 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
Solar Pro 4 costs less
Repository review
50K input + 3K output tokens
Solar Pro 4 costs less
Agent loop
200K input + 10K output tokens
Solar Pro 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 | Thinking Machines Inkling Small | Upstage Solar Pro 4 |
|---|---|---|
| Maker | Thinking Machines | Upstage |
| Weights | Open weights | No public weights listed |
| Released | July 30, 2026 | August 10, 2026 |
| Context window | 524K | 524K |
| Input $/Mtok | $0.45 | $0.15 |
| Output $/Mtok | $1.20 | $0.60 |
| Coding index | 27.3 | Not benchmarked |
| Independent measurements behind it | 4 | 1 |
| Cost per solved task | $0.16 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Inkling Small better than Solar Pro 4 for coding?
Only Inkling Small has a coding score, 27.3 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding. Pick Solar Pro 4 for output tokens 2.0x cheaper ($0.60 vs $1.20 per million) and work measured by AA Intelligence Index or LMArena Text: Korean, where it leads.
Which is cheaper, Inkling Small or Solar Pro 4?
Inkling Small costs $0.45 per million input tokens and $1.20 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for Inkling Small only.
Which has the bigger context window, Inkling Small or Solar Pro 4?
Neither: both take 524K tokens.
How many benchmarks is the Inkling Small vs Solar Pro 4 comparison based on?
37 benchmarks have a result for both models as of October 22, 2026. Inkling Small's coding index rests on 4 independent benchmarks and Solar Pro 4's on 1. Where only one model has a result, the page says so instead of naming a winner.