Inkling vs Solar Pro 4
Solar Pro 4 leads Inkling on the Artificial Analysis Intelligence Index, 28.2 to 25.0, and Solar Pro 4 costs 6.8x less per output token ($0.60 vs $4.05 per million). Updated October 22, 2026; 45 benchmarks have a result for both.
Inkling or Solar Pro 4: which to pick
Only Inkling has a coding score, 31.5 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 6.8x cheaper ($0.60 vs $4.05 per million) and work measured by AA Coding Index or SciCode, where it leads.
- Shared results
- 45
- Inkling only
- 57
- Solar Pro 4 only
- 0
- 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
No call
Only Inkling 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 25.0.
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
Inkling
Inkling leads, 1224 against 1176.
Same board, both measured
General
Vals Index
No call
Only Inkling has a Vals Index result, 29.0%.
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 $0.0030, Solar Pro 4 $0.0004 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
- Inkling 31.5 from 6 benchmarks, Solar Pro 4 not benchmarked.
- Widest category
- Agentic work, 11.4 points apart on average over 1 shared benchmark.
- Widest single gap
- ALE-Bench: Inkling 946.0 against Solar Pro 4 179.3, 25.6 points apart on a 0 to 100 scale.
- Output price
- Inkling $4.05 against Solar Pro 4 $0.60 per million output tokens, 6.8x 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 | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 6 | 2 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 4 | 1 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| Web design | 3 | 3 | ||
| General | 18 | 0 | ||
| All shared boards | 38 | 7 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index62
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| LiveBench coding | 64.0% | Not measured | Only Inkling measured |
| LMArena WebDev | 1414 | 1371 | Inkling |
| AA Coding Index | 52.1 | 52.7 | Solar Pro 4 |
| LiveCodeBench (Vals AI) | 85.5% | Not measured | Only Inkling measured |
| SWE-bench Verified (Vals AI) | 77.6% | Not measured | Only Inkling measured |
| Terminal-Bench 4 (Vals AI) | 0.5% | Not measured | Only Inkling measured |
| Vibe Code Bench (Vals AI) | 19.2% | Not measured | Only Inkling measured |
| Code migration (Vals AI) | 11.8% | Not measured | Only Inkling measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Inkling measured |
| IOI (Vals AI) | 14.9% | Not measured | Only Inkling measured |
| Terminal-Bench 2.1 (Vals AI) | 47.6% | Not measured | Only Inkling measured |
| Vibe Code Bench 1-100 (Vals AI) | 7.3% | Not measured | Only Inkling measured |
| SkillsBench (Vals AI) | 26.1% | Not measured | Only Inkling measured |
| CyberBench (Vals AI) | 66.8% | Not measured | Only Inkling measured |
| SciCode | 47.0% | 48.0% | Solar Pro 4 |
| FrontierCode | 14.0% | Not measured | Only Inkling measured |
| FrontierSWE | 4.1% | Not measured | Only Inkling measured |
| WeirdML | 32.3% | Not measured | Only Inkling measured |
| ALE-Bench | 946.0 | 179.3 | Inkling |
| LMArena Text: coding | 1466 | 1438 | Inkling |
| LMArena Text: software and IT | 1465 | 1431 | Inkling |
| LMArena WebDev: React | 1404 | 1363 | Inkling |
| LMArena WebDev: HTML | 1399 | 1371 | Inkling |
| Neither model has a result on the other 16 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 25.0 | 28.2 | Solar Pro 4 |
| Epoch Capabilities Index | 148.4 | Not measured | Only Inkling measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Agentic Index | 22.5 | Not measured | Only Inkling measured |
| Design Arena: agents building web apps | 1196 | 1105 | Inkling |
| LiveBench research | 59.9% | Not measured | Only Inkling measured |
| LiveBench browser | 16.0% | Not measured | Only Inkling measured |
| LiveBench long agentic | 14.1% | Not measured | Only Inkling measured |
| SREBench (Vals AI) | 0.0% | Not measured | Only Inkling measured |
| Finance Agent (Vals AI) | 46.6% | Not measured | Only Inkling measured |
| Tax Agent Bench (Vals AI) | 15.3% | Not measured | Only Inkling measured |
| Legal Research Bench (Vals AI) | 28.4% | Not measured | Only Inkling measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 3.8% | Not measured | Only Inkling measured |
| Excel Modeling Benchmark (Vals AI) | 38.4% | Not measured | Only Inkling measured |
| APEX-Agents | 33.8% | Not measured | Only Inkling measured |
| Neither model has a result on the other 29 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index41
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| GPQA Diamond | 87.1% | Not measured | Only Inkling measured |
| LiveBench reasoning | 78.3% | Not measured | Only Inkling measured |
| MMMU Pro (Vals AI) | 78.5% | Not measured | Only Inkling measured |
| GPQA Diamond (Artificial Analysis run) | 87.2% | 89.1% | Solar Pro 4 |
| Humanity's Last Exam (Artificial Analysis run) | 31.9% | 29.8% | Inkling |
| GPQA Diamond (Epoch AI run) | 88.3% | Not measured | Only Inkling measured |
| ARC-AGI | 79.5% | Not measured | Only Inkling measured |
| ARC-AGI-2 | 36.5% | Not measured | Only Inkling measured |
| SimpleBench | 50.0% | Not measured | Only Inkling measured |
| Chess puzzles | 21.0% | Not measured | Only Inkling measured |
| LMArena Text: hard prompts | 1451 | 1400 | Inkling |
| LMArena Text: expert | 1466 | 1428 | Inkling |
| LMArena Text: hard prompts in English | 1448 | 1427 | Inkling |
| Neither model has a result on the other 9 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 88.9% | Not measured | Only Inkling measured |
| FrontierMath, tiers 1 to 3 | 33.3% | Not measured | Only Inkling measured |
| FrontierMath, tier 4 | 4.9% | Not measured | Only Inkling measured |
| ProofBench | 0.0% | Not measured | Only Inkling measured |
| LMArena Text: math | 1479 | 1421 | Inkling |
| LMArena Text: mathematical work | 1460 | 1427 | Inkling |
| 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 | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 86.3% | Not measured | Only Inkling measured |
| LegalBench (Vals AI) | 83.0% | Not measured | Only Inkling measured |
| CorpFin (Vals AI) | 68.6% | Not measured | Only Inkling measured |
| TaxEval (Vals AI) | 75.3% | Not measured | Only Inkling measured |
| MortgageTax (Vals AI) | 64.0% | Not measured | Only Inkling measured |
| MedCode (Vals AI) | 41.2% | Not measured | Only Inkling measured |
| SimpleQA Verified | 40.3% | Not measured | Only Inkling measured |
| LMArena Text: science | 1455 | 1404 | Inkling |
| LMArena Text: medicine and healthcare | 1447 | 1374 | Inkling |
| LMArena Text: legal and government | 1448 | 1383 | Inkling |
| LMArena Text: business and finance | 1438 | 1381 | Inkling |
| Neither model has a result on the other 7 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index33
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1224 | 1176 | Inkling |
| Design Arena: UI components | 1198 | 1147 | Inkling |
| Design Arena: game dev | 1165 | 1169 | Solar Pro 4 |
| Design Arena: data viz | 1156 | 1177 | Solar Pro 4 |
| Design Arena: 3D | 1160 | 1178 | Solar Pro 4 |
| Design Arena: all code categories | 1205 | 1182 | Inkling |
| Design Arena: SVG | 1108 | Not measured | Only Inkling measured |
| Design Arena: ASCII art | 1089 | Not measured | Only Inkling measured |
| LiveBench design | 58.3% | Not measured | Only Inkling measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index180
| Benchmark | Inkling | Solar Pro 4 | Leader |
|---|---|---|---|
| Vals Index | 29.0% | Not measured | Only Inkling measured |
| LiveBench data analysis | 72.8% | Not measured | Only Inkling measured |
| Public Benefits Bench (Vals AI) | 58.5% | Not measured | Only Inkling measured |
| SAGE (Vals AI) | 36.5% | Not measured | Only Inkling measured |
| MedScribe (Vals AI) | 85.4% | Not measured | Only Inkling measured |
| Vals Multimodal Index | 49.4% | Not measured | Only Inkling measured |
| Long context reasoning (AA-LCR) | 77.3% | 70.7% | Inkling |
| DTBench | 87.5% | Not measured | Only Inkling measured |
| LMCA | 37.6% | Not measured | Only Inkling measured |
| LMArena Text | 1442 | 1388 | Inkling |
| LMArena Text: instruction following | 1425 | 1375 | Inkling |
| LMArena Text: creative writing | 1390 | 1317 | Inkling |
| LMArena Text: English | 1442 | 1414 | Inkling |
| LMArena Text: non-English | 1434 | 1363 | Inkling |
| LMArena Text: Chinese | 1493 | 1422 | Inkling |
| LMArena Text: German | 1445 | 1358 | Inkling |
| LMArena Text: Japanese | 1429 | 1320 | Inkling |
| LMArena Text: Korean | 1403 | 1383 | Inkling |
| LMArena Text: French | 1455 | 1400 | Inkling |
| LMArena Text: Spanish | 1449 | 1409 | Inkling |
| LMArena Text: Russian | 1430 | 1357 | Inkling |
| LMArena Text: Polish | 1450 | 1304 | Inkling |
| LMArena Text: multi-turn | 1437 | 1385 | Inkling |
| LMArena Text: longer queries | 1435 | 1382 | Inkling |
| LMArena Text: writing and language | 1404 | 1344 | Inkling |
| LMArena Text: entertainment and media | 1394 | 1332 | Inkling |
| 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 | Inkling | 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 | Upstage Solar Pro 4 |
|---|---|---|
| Maker | Thinking Machines | Upstage |
| Weights | Open weights | No public weights listed |
| Released | July 17, 2026 | August 10, 2026 |
| Context window | 524K | 524K |
| Input $/Mtok | $0.975 | $0.15 |
| Output $/Mtok | $4.05 | $0.60 |
| Coding index | 31.5 | Not benchmarked |
| Independent measurements behind it | 6 | 1 |
| Cost per solved task | $0.76 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Inkling better than Solar Pro 4 for coding?
Only Inkling has a coding score, 31.5 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 6.8x cheaper ($0.60 vs $4.05 per million) and work measured by AA Coding Index or SciCode, where it leads.
Which is cheaper, Inkling or Solar Pro 4?
Inkling costs $0.975 per million input tokens and $4.05 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for Inkling only.
Which has the bigger context window, Inkling or Solar Pro 4?
Neither: both take 524K tokens.
How many benchmarks is the Inkling vs Solar Pro 4 comparison based on?
45 benchmarks have a result for both models as of October 22, 2026. Inkling's coding index rests on 6 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.