Grok 4.20 vs Inkling
Grok 4.20 leads Inkling on coding, 33.3 to 31.5 on the Vibe Coding Index, and Grok 4.20 costs 1.6x less per output token ($2.50 vs $4.05 per million). Updated October 21, 2026; 39 benchmarks have a result for both.
Grok 4.20 or Inkling: which to pick
Grok 4.20 and Inkling are level for coding, 33.3 against 31.5 on the Vibe Coding Index, so price and context decide.
Pick Inkling for work measured by LiveCodeBench (Vals AI) or SWE-bench Verified (Vals AI), where it leads. Pick Grok 4.20 for output tokens 1.6x cheaper ($2.50 vs $4.05 per million) and a lower cost per solved task ($0.72 against $0.76).
- Shared results
- 39
- Grok 4.20 only
- 16
- Inkling only
- 63
- Like-for-like categories
- 7 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
Level: 33.3 against 31.5, inside 2 points.
2 and 6 benchmarks behind the scores
Intelligence
AA Intelligence Index
Grok 4.20
Grok 4.20 leads, 25.7 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
Grok 4.20
Grok 4.20 leads, 88.6% against 87.1%.
Same board, both measured
Math
AIME
No call
Only Grok 4.20 has a AIME result, 96.5%.
Directional only
Knowledge
MMLU Pro
Inkling
Inkling leads, 86.3% against 86.3%.
Same board, both measured
Web design
Design Arena: websites
Grok 4.20
Grok 4.20 leads, 1229 against 1224.
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
Grok 4.20
Grok 4.20 takes 2M tokens against 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Grok 4.20
Grok 4.20 $0.0025, Inkling $0.0030 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Grok 4.20
Grok 4.20 $0.72, Inkling $0.76.
Published attempt cost and pass rate
At a glance
- Coding index
- Grok 4.20 33.3 from 2 benchmarks, Inkling 31.5 from 6 benchmarks.
- Widest category
- Agentic work, 14.8 points apart on average over 5 shared benchmarks.
- Widest single gap
- ARC-AGI-2: Grok 4.20 65.1% against Inkling 36.5%, 28.6 points apart on a 0 to 100 scale.
- Output price
- Grok 4.20 $2.50 against Inkling $4.05 per million output tokens, 1.6x apart.
- Context window
- Grok 4.20 takes 2M 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 | Grok 4.20 | Bars | Inkling | Ties |
|---|---|---|---|---|
| Coding | 1 | 5 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 0 | 5 | ||
| Reasoning | 6 | 0 | ||
| Knowledge | 0 | 6 | ||
| Web design | 7 | 1 | ||
| General | 3 | 3 | ||
| All shared boards | 19 | 20 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index15
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 64.0% | Only Inkling measured |
| LMArena WebDev | Not measured | 1414 | Only Inkling measured |
| AA Coding Index | Not measured | 52.1 | Only Inkling measured |
| LiveCodeBench (Vals AI) | 84.3% | 85.5% | Inkling |
| SWE-bench Verified (Vals AI) | 72.2% | 77.6% | Inkling |
| Terminal-Bench 4 (Vals AI) | Not measured | 0.5% | Only Inkling measured |
| Vibe Code Bench (Vals AI) | 4.1% | 19.2% | Inkling |
| Code migration (Vals AI) | 0.3% | 11.8% | Inkling |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Inkling measured |
| IOI (Vals AI) | Not measured | 14.9% | Only Inkling measured |
| Terminal-Bench 2.1 (Vals AI) | 44.2% | 47.6% | Inkling |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 7.3% | Only Inkling measured |
| SkillsBench (Vals AI) | Not measured | 26.1% | Only Inkling measured |
| CyberBench (Vals AI) | Not measured | 66.8% | Only Inkling measured |
| SciCode | Not measured | 47.0% | Only Inkling measured |
| Terminal-Bench Hard (Artificial Analysis run) | 37.9% | Not measured | Only Grok 4.20 measured |
| Terminal-Bench | 57.3% | Not measured | Only Grok 4.20 measured |
| FrontierCode | Not measured | 14.0% | Only Inkling measured |
| FrontierSWE | Not measured | 4.1% | Only Inkling measured |
| WeirdML | 52.3% | 32.3% | Grok 4.20 |
| ALE-Bench | Not measured | 946.0 | Only Inkling measured |
| LMArena Text: coding | Not measured | 1466 | Only Inkling measured |
| LMArena Text: software and IT | Not measured | 1465 | Only Inkling measured |
| LMArena WebDev: React | Not measured | 1404 | Only Inkling measured |
| LMArena WebDev: HTML | Not measured | 1399 | Only Inkling measured |
| Neither model has a result on the other 14 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| AA Intelligence Index | 25.7 | 25.0 | Grok 4.20 |
| Epoch Capabilities Index | 152.1 | 148.4 | Grok 4.20 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index05
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 22.5 | Only Inkling measured |
| Design Arena: agents building web apps | 1144 | 1196 | Inkling |
| Design Arena: agents building full-stack apps | 1054 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building mobile apps | 1090 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building Android apps | 1052 | Not measured | Only Grok 4.20 measured |
| Design Arena: agents building Godot games | 1089 | Not measured | Only Grok 4.20 measured |
| Design Arena: HTML slides | 1180 | Not measured | Only Grok 4.20 measured |
| LiveBench research | Not measured | 59.9% | Only Inkling measured |
| LiveBench browser | Not measured | 16.0% | Only Inkling measured |
| LiveBench long agentic | Not measured | 14.1% | Only Inkling measured |
| SREBench (Vals AI) | Not measured | 0.0% | Only Inkling measured |
| Finance Agent (Vals AI) | 28.5% | 46.6% | Inkling |
| Tax Agent Bench (Vals AI) | 7.0% | 15.3% | Inkling |
| Legal Research Bench (Vals AI) | 13.9% | 28.4% | Inkling |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 3.8% | Only Inkling measured |
| Excel Modeling Benchmark (Vals AI) | 11.7% | 38.4% | Inkling |
| τ²-Bench Telecom | 93.0% | Not measured | Only Grok 4.20 measured |
| APEX-Agents | Not measured | 33.8% | Only Inkling measured |
| Vending-Bench 2 | $4,663 | Not measured | Only Grok 4.20 measured |
| Neither model has a result on the other 22 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| GPQA Diamond | 88.6% | 87.1% | Grok 4.20 |
| LiveBench reasoning | Not measured | 78.3% | Only Inkling measured |
| MMMU Pro (Vals AI) | 83.5% | 78.5% | Grok 4.20 |
| GPQA Diamond (Artificial Analysis run) | 91.1% | 87.2% | Grok 4.20 |
| Humanity's Last Exam (Artificial Analysis run) | 34.5% | 31.9% | Grok 4.20 |
| GPQA Diamond (Epoch AI run) | Not measured | 88.3% | Only Inkling measured |
| ARC-AGI | 89.5% | 79.5% | Grok 4.20 |
| ARC-AGI-2 | 65.1% | 36.5% | Grok 4.20 |
| SimpleBench | Not measured | 50.0% | Only Inkling measured |
| Chess puzzles | Not measured | 21.0% | Only Inkling measured |
| LMArena Text: hard prompts | Not measured | 1451 | Only Inkling measured |
| LMArena Text: expert | Not measured | 1466 | Only Inkling measured |
| LMArena Text: hard prompts in English | Not measured | 1448 | Only Inkling measured |
| Kagi LLM Benchmark | 75.0% | Not measured | Only Grok 4.20 measured |
| Neither model has a result on the other 8 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| AIME | 96.5% | Not measured | Only Grok 4.20 measured |
| OTIS Mock AIME | Not measured | 88.9% | Only Inkling measured |
| FrontierMath, tiers 1 to 3 | Not measured | 33.3% | Only Inkling measured |
| FrontierMath, tier 4 | Not measured | 4.9% | Only Inkling measured |
| ProofBench | Not measured | 0.0% | Only Inkling measured |
| LMArena Text: math | Not measured | 1479 | Only Inkling measured |
| LMArena Text: mathematical work | Not measured | 1460 | Only Inkling measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| MMLU Pro | 86.3% | 86.3% | Inkling |
| LegalBench (Vals AI) | 77.7% | 83.0% | Inkling |
| CaseLaw (Vals AI) | 54.4% | Not measured | Only Grok 4.20 measured |
| CorpFin (Vals AI) | 63.7% | 68.6% | Inkling |
| TaxEval (Vals AI) | 74.1% | 75.3% | Inkling |
| MortgageTax (Vals AI) | 45.4% | 64.0% | Inkling |
| MedQA (Vals AI) | 94.5% | Not measured | Only Grok 4.20 measured |
| MedCode (Vals AI) | 32.2% | 41.2% | Inkling |
| SimpleQA Verified | Not measured | 40.3% | Only Inkling measured |
| LMArena Text: science | Not measured | 1455 | Only Inkling measured |
| LMArena Text: medicine and healthcare | Not measured | 1447 | Only Inkling measured |
| LMArena Text: legal and government | Not measured | 1448 | Only Inkling measured |
| LMArena Text: business and finance | Not measured | 1438 | Only Inkling measured |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index71
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| Design Arena: websites | 1229 | 1224 | Grok 4.20 |
| Design Arena: UI components | 1199 | 1201 | Inkling |
| Design Arena: game dev | 1192 | 1166 | Grok 4.20 |
| Design Arena: data viz | 1217 | 1159 | Grok 4.20 |
| Design Arena: 3D | 1193 | 1161 | Grok 4.20 |
| Design Arena: all code categories | 1221 | 1206 | Grok 4.20 |
| Design Arena: SVG | 1164 | 1110 | Grok 4.20 |
| Design Arena: ASCII art | 1174 | 1089 | Grok 4.20 |
| LiveBench design | Not measured | 58.3% | Only Inkling measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index33
| Benchmark | Grok 4.20 | Inkling | Leader |
|---|---|---|---|
| Vals Index | Not measured | 29.0% | Only Inkling measured |
| LiveBench data analysis | Not measured | 72.8% | Only Inkling measured |
| Public Benefits Bench (Vals AI) | Not measured | 58.5% | Only Inkling measured |
| SAGE (Vals AI) | 38.2% | 36.5% | Grok 4.20 |
| MedScribe (Vals AI) | 63.4% | 85.4% | Inkling |
| Vals Multimodal Index | 39.1% | 49.4% | Inkling |
| IFBench | 81.2% | Not measured | Only Grok 4.20 measured |
| Long context reasoning (AA-LCR) | 69.0% | 77.3% | Inkling |
| DTBench | 90.1% | 87.5% | Grok 4.20 |
| LMCA | 38.7% | 37.6% | Grok 4.20 |
| CL-bench | 22.2% | Not measured | Only Grok 4.20 measured |
| CL-bench Life | 11.9% | Not measured | Only Grok 4.20 measured |
| LMArena Text | Not measured | 1442 | Only Inkling measured |
| LMArena Text: instruction following | Not measured | 1425 | Only Inkling measured |
| LMArena Text: creative writing | Not measured | 1390 | Only Inkling measured |
| LMArena Text: English | Not measured | 1442 | Only Inkling measured |
| LMArena Text: non-English | Not measured | 1434 | Only Inkling measured |
| LMArena Text: Chinese | Not measured | 1493 | Only Inkling measured |
| LMArena Text: German | Not measured | 1445 | Only Inkling measured |
| LMArena Text: Japanese | Not measured | 1429 | Only Inkling measured |
| LMArena Text: Korean | Not measured | 1403 | Only Inkling measured |
| LMArena Text: French | Not measured | 1455 | Only Inkling measured |
| LMArena Text: Spanish | Not measured | 1449 | Only Inkling measured |
| LMArena Text: Russian | Not measured | 1430 | Only Inkling measured |
| LMArena Text: Polish | Not measured | 1450 | Only Inkling measured |
| LMArena Text: multi-turn | Not measured | 1437 | Only Inkling measured |
| LMArena Text: longer queries | Not measured | 1435 | Only Inkling measured |
| LMArena Text: writing and language | Not measured | 1404 | Only Inkling measured |
| LMArena Text: entertainment and media | Not measured | 1394 | Only Inkling 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 | Grok 4.20 | 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
Grok 4.20 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 | SpaceXAI Grok 4.20 | Thinking Machines Inkling |
|---|---|---|
| Maker | xAI | Thinking Machines |
| Weights | No public weights listed | Open weights |
| Released | March 31, 2026 | July 17, 2026 |
| Context window | 2M | 524K |
| Input $/Mtok | $1.25 | $0.975 |
| Output $/Mtok | $2.50 | $4.05 |
| Coding index | 33.3 | 31.5 |
| Independent measurements behind it | 2 | 6 |
| Cost per solved task | $0.72 | $0.76 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Grok 4.20 better than Inkling for coding?
Grok 4.20 and Inkling are level for coding, 33.3 against 31.5 on the Vibe Coding Index, so price and context decide. Pick Inkling for work measured by LiveCodeBench (Vals AI) or SWE-bench Verified (Vals AI), where it leads. Pick Grok 4.20 for output tokens 1.6x cheaper ($2.50 vs $4.05 per million) and a lower cost per solved task ($0.72 against $0.76).
Which is cheaper, Grok 4.20 or Inkling?
Grok 4.20 costs $1.25 per million input tokens and $2.50 per million output tokens; Inkling costs $0.975 and $4.05. Per solved SWE-bench Verified task, Grok 4.20 costs $0.72 and Inkling $0.76.
Which has the bigger context window, Grok 4.20 or Inkling?
Grok 4.20, with 2M tokens against 524K.
How many benchmarks is the Grok 4.20 vs Inkling comparison based on?
39 benchmarks have a result for both models as of October 21, 2026. Grok 4.20's coding index rests on 2 independent benchmarks and Inkling's on 6. Where only one model has a result, the page says so instead of naming a winner.