Inkling 2 Small vs Solar Pro 4
Inkling 2 Small leads Solar Pro 4 on the Artificial Analysis Intelligence Index, 30.6 to 28.2, and Solar Pro 4 costs 1.7x less per output token ($0.60 vs $1.00 per million). Updated November 14, 2026; 30 benchmarks have a result for both.
Inkling 2 Small or Solar Pro 4: which to pick
Only Inkling 2 Small has a coding score, 48.9 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 1.7x cheaper ($0.60 vs $1.00 per million) and work measured by LMArena Text: hard prompts in English, where it leads.
- Shared results
- 30
- Inkling 2 Small only
- 21
- Solar Pro 4 only
- 21
- 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
No call
Only Inkling 2 Small has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Inkling 2 Small
Inkling 2 Small leads, 30.6 against 28.2.
Same board, both measured
Web design
Design Arena: websites
No call
Only Solar Pro 4 has a Design Arena: websites result, 1163.
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 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Solar Pro 4
Inkling 2 Small $0.0008, Solar Pro 4 $0.0004 per turn.
List prices
At a glance
- Coding index
- Inkling 2 Small 48.9 from 3 benchmarks, Solar Pro 4 not benchmarked.
- Widest category
- Coding, 20.3 points apart on average over 8 shared benchmarks.
- Widest single gap
- GDPval-AA: Inkling 2 Small 1630 against Solar Pro 4 1106, 43.7 points apart on a 0 to 100 scale.
- Output price
- Inkling 2 Small $1.00 against Solar Pro 4 $0.60 per million output tokens, 1.7x apart.
- Context window
- Inkling 2 Small takes 1.05M tokens, Solar Pro 4 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 | Inkling 2 Small | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 8 | 0 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 5 | 1 | ||
| Knowledge | 3 | 0 | ||
| General | 12 | 0 | ||
| All shared boards | 29 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index80
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| LMArena WebDev | 1647 | 1369 | Inkling 2 Small |
| AA Coding Index | Not measured | 52.7 | Only Solar Pro 4 measured |
| Terminal-Bench 4 (Vals AI) | 12.6% | Not measured | Only Inkling 2 Small measured |
| Vibe Code Bench (Vals AI) | 81.5% | Not measured | Only Inkling 2 Small measured |
| ProgramBench (Vals AI) | 0.5% | Not measured | Only Inkling 2 Small measured |
| SWE-bench Multimodal (Vals AI) | 43.1% | Not measured | Only Inkling 2 Small measured |
| CyberBench (Vals AI) | 72.7% | Not measured | Only Inkling 2 Small measured |
| SciCode | 52.3% | 48.0% | Inkling 2 Small |
| Terminal-Bench 4.0 (Artificial Analysis run) | 13.1% | 0.0% | Inkling 2 Small |
| FrontierCode 2.0 | 25.4% | 4.1% | Inkling 2 Small |
| ALE-Bench | Not measured | 179.3 | Only Solar Pro 4 measured |
| LMArena Text: coding | 1455 | 1437 | Inkling 2 Small |
| LMArena Text: software and IT | 1443 | 1428 | Inkling 2 Small |
| LMArena WebDev: React | 1660 | 1361 | Inkling 2 Small |
| LMArena WebDev: HTML | 1661 | 1371 | Inkling 2 Small |
| SWE-Bench Pro V2 | 97.7% | Not measured | Only Inkling 2 Small measured |
| Neither model has a result on the other 36 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 30.6 | 28.2 | Inkling 2 Small |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1081 | Only Solar Pro 4 measured |
| SREBench (Vals AI) | 1.9% | Not measured | Only Inkling 2 Small measured |
| Tax Agent Bench (Vals AI) | 38.9% | Not measured | Only Inkling 2 Small measured |
| Legal Research Bench (Vals AI) | 46.6% | Not measured | Only Inkling 2 Small measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 21.7% | Not measured | Only Inkling 2 Small measured |
| BioMysteryBench (Vals AI) | 70.0% | Not measured | Only Inkling 2 Small measured |
| Terminal-Bench-Science (Vals AI) | 2.9% | Not measured | Only Inkling 2 Small measured |
| Vals Science Index | 32.7% | Not measured | Only Inkling 2 Small measured |
| APEX-Agents | 46.8% | Not measured | Only Inkling 2 Small measured |
| MCP Atlas | 85.4% | Not measured | Only Inkling 2 Small measured |
| Neither model has a result on the other 34 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index51
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| MysteryMechanism (Vals AI) | 25.2% | Not measured | Only Inkling 2 Small measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 89.1% | Only Solar Pro 4 measured |
| Humanity's Last Exam (Artificial Analysis run) | 44.1% | 29.8% | Inkling 2 Small |
| HLE-Diamond (Artificial Analysis run) | 28.7% | 4.7% | Inkling 2 Small |
| CritPt v2, hard subset (Artificial Analysis run) | 35.0% | 18.0% | Inkling 2 Small |
| ARC-AGI | 96.5% | Not measured | Only Inkling 2 Small measured |
| ARC-AGI-2 | 81.7% | Not measured | Only Inkling 2 Small measured |
| LMArena Text: hard prompts | 1421 | 1399 | Inkling 2 Small |
| LMArena Text: expert | 1478 | 1425 | Inkling 2 Small |
| LMArena Text: hard prompts in English | 1424 | 1428 | Solar Pro 4 |
| Neither model has a result on the other 16 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| LMArena Text: math | Not measured | 1416 | Only Solar Pro 4 measured |
| LMArena Text: mathematical work | Not measured | 1424 | Only Solar Pro 4 measured |
| MathArena | 42.4% | Not measured | Only Inkling 2 Small measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| AA-Omniscience | 16.1 | 1.4 | Inkling 2 Small |
| LMArena Text: science | 1409 | 1402 | Inkling 2 Small |
| LMArena Text: medicine and healthcare | Not measured | 1376 | Only Solar Pro 4 measured |
| LMArena Text: legal and government | Not measured | 1386 | Only Solar Pro 4 measured |
| LMArena Text: business and finance | 1415 | 1380 | Inkling 2 Small |
| Neither model has a result on the other 16 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1163 | Only Solar Pro 4 measured |
| Design Arena: UI components | Not measured | 1140 | Only Solar Pro 4 measured |
| Design Arena: game dev | Not measured | 1168 | Only Solar Pro 4 measured |
| Design Arena: data viz | Not measured | 1174 | Only Solar Pro 4 measured |
| Design Arena: 3D | Not measured | 1159 | Only Solar Pro 4 measured |
| Design Arena: all code categories | Not measured | 1170 | 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 index120
| Benchmark | Inkling 2 Small | Solar Pro 4 | Leader |
|---|---|---|---|
| Vals Index | 56.1% | Not measured | Only Inkling 2 Small measured |
| SAGE (Vals AI) | 88.6% | Not measured | Only Inkling 2 Small measured |
| Long context reasoning (AA-LCR) | 83.3% | 70.7% | Inkling 2 Small |
| GDPval-AA | 1630 | 1106 | Inkling 2 Small |
| LMArena Text | 1403 | 1388 | Inkling 2 Small |
| LMArena Text: instruction following | 1408 | 1375 | Inkling 2 Small |
| LMArena Text: creative writing | 1348 | 1317 | Inkling 2 Small |
| LMArena Text: English | 1418 | 1415 | Inkling 2 Small |
| LMArena Text: non-English | 1390 | 1362 | Inkling 2 Small |
| LMArena Text: Chinese | Not measured | 1428 | Only Solar Pro 4 measured |
| LMArena Text: German | Not measured | 1351 | Only Solar Pro 4 measured |
| LMArena Text: Japanese | Not measured | 1323 | Only Solar Pro 4 measured |
| LMArena Text: Korean | Not measured | 1382 | Only Solar Pro 4 measured |
| LMArena Text: French | Not measured | 1409 | Only Solar Pro 4 measured |
| LMArena Text: Spanish | Not measured | 1412 | Only Solar Pro 4 measured |
| LMArena Text: Russian | 1377 | 1353 | Inkling 2 Small |
| LMArena Text: Polish | Not measured | 1302 | Only Solar Pro 4 measured |
| LMArena Text: multi-turn | 1408 | 1389 | Inkling 2 Small |
| LMArena Text: longer queries | 1403 | 1380 | Inkling 2 Small |
| LMArena Text: writing and language | 1381 | 1344 | Inkling 2 Small |
| LMArena Text: entertainment and media | 1359 | 1330 | Inkling 2 Small |
| Neither model has a result on the other 28 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Inkling 2 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 2 Small | Upstage Solar Pro 4 |
|---|---|---|
| Maker | Thinking Machines | Upstage |
| Weights | Open weights | No public weights listed |
| Released | November 9, 2026 | August 10, 2026 |
| Context window | 1.05M | 524K |
| Input $/Mtok | $0.30 | $0.15 |
| Output $/Mtok | $1.00 | $0.60 |
| Coding index | 48.9 | Not benchmarked |
| Independent measurements behind it | 3 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Inkling 2 Small better than Solar Pro 4 for coding?
Only Inkling 2 Small has a coding score, 48.9 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 1.7x cheaper ($0.60 vs $1.00 per million) and work measured by LMArena Text: hard prompts in English, where it leads.
Which is cheaper, Inkling 2 Small or Solar Pro 4?
Inkling 2 Small costs $0.30 per million input tokens and $1.00 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for neither of them.
Which has the bigger context window, Inkling 2 Small or Solar Pro 4?
Inkling 2 Small, with 1.05M tokens against 524K.
How many benchmarks is the Inkling 2 Small vs Solar Pro 4 comparison based on?
30 benchmarks have a result for both models as of November 14, 2026. Inkling 2 Small's coding index rests on 3 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.