Grok 4.20 vs Kimi K2.6
Kimi K2.6 leads Grok 4.20 on coding, 52.1 to 33.3 on the Vibe Coding Index, and Grok 4.20 costs 1.6x less per output token ($2.50 vs $4.00 per million). Updated October 21, 2026; 47 benchmarks have a result for both.
Grok 4.20 or Kimi K2.6: which to pick
Pick Kimi K2.6 for coding: it scores 52.1 on the Vibe Coding Index against 33.3 for Grok 4.20.
Pick Grok 4.20 for output tokens 1.6x cheaper ($2.50 vs $4.00 per million) and a larger context window (2M against 262K tokens).
- Shared results
- 47
- Grok 4.20 only
- 8
- Kimi K2.6 only
- 62
- 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
Kimi K2.6
Kimi K2.6 scores 52.1 against 33.3.
2 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
Kimi K2.6
Kimi K2.6 leads, 27.0 against 25.7.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Kimi K2.6 has a AA Agentic Index result, 20.5.
Directional only
Reasoning
GPQA Diamond
Kimi K2.6
Kimi K2.6 leads, 89.1% against 88.6%.
Same board, both measured
Math
AIME
No call
Only Grok 4.20 has a AIME result, 96.5%.
Directional only
Knowledge
MMLU Pro
Kimi K2.6
Kimi K2.6 leads, 87.6% against 86.3%.
Same board, both measured
Web design
Design Arena: websites
Kimi K2.6
Kimi K2.6 leads, 1269 against 1229.
Same board, both measured
Long documents
Listed context window
Grok 4.20
Grok 4.20 takes 2M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Grok 4.20
Grok 4.20 $0.0025, Kimi K2.6 $0.0029 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Kimi K2.6
Grok 4.20 $0.72, Kimi K2.6 $0.35.
Published attempt cost and pass rate
At a glance
- Coding index
- Grok 4.20 33.3 from 2 benchmarks, Kimi K2.6 52.1 from 3 benchmarks.
- Widest category
- Coding, 12.4 points apart on average over 7 shared benchmarks.
- Widest single gap
- Excel Modeling Benchmark (Vals AI): Grok 4.20 11.7% against Kimi K2.6 57.9%, 46.1 points apart on a 0 to 100 scale.
- Output price
- Grok 4.20 $2.50 against Kimi K2.6 $4.00 per million output tokens, 1.6x apart.
- Context window
- Grok 4.20 takes 2M tokens, Kimi K2.6 262K.
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 | Kimi K2.6 | Ties |
|---|---|---|---|---|
| Coding | 0 | 7 | ||
| Intelligence | 1 | 1 | ||
| Agentic work | 0 | 12 | ||
| Reasoning | 0 | 3 | 1 tie | |
| Knowledge | 0 | 7 | ||
| Web design | 1 | 7 | ||
| General | 2 | 5 | ||
| All shared boards | 4 | 42 | 1 tie |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index07
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1509 | Only Kimi K2.6 measured |
| AA Coding Index | Not measured | 61.8 | Only Kimi K2.6 measured |
| LiveCodeBench (Vals AI) | 84.3% | 86.8% | Kimi K2.6 |
| SWE-bench Verified (Vals AI) | 72.2% | 76.2% | Kimi K2.6 |
| Vibe Code Bench (Vals AI) | 4.1% | 37.9% | Kimi K2.6 |
| Code migration (Vals AI) | 0.3% | 27.8% | Kimi K2.6 |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Kimi K2.6 measured |
| Terminal-Bench 2.1 (Vals AI) | 44.2% | 53.6% | Kimi K2.6 |
| SciCode | Not measured | 51.5% | Only Kimi K2.6 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 37.9% | 43.9% | Kimi K2.6 |
| Terminal-Bench | 57.3% | Not measured | Only Grok 4.20 measured |
| WeirdML | 52.3% | 55.9% | Kimi K2.6 |
| ALE-Bench | Not measured | 1092.7 | Only Kimi K2.6 measured |
| LMArena Text: coding | Not measured | 1489 | Only Kimi K2.6 measured |
| LMArena Text: software and IT | Not measured | 1484 | Only Kimi K2.6 measured |
| LMArena WebDev: React | Not measured | 1505 | Only Kimi K2.6 measured |
| LMArena WebDev: HTML | Not measured | 1485 | Only Kimi K2.6 measured |
| LMArena WebDev: from an image | Not measured | 1521 | Only Kimi K2.6 measured |
| Neither model has a result on the other 21 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| AA Intelligence Index | 25.7 | 27.0 | Kimi K2.6 |
| Epoch Capabilities Index | 152.1 | 150.9 | Grok 4.20 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index012
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 20.5 | Only Kimi K2.6 measured |
| Design Arena: agents building web apps | 1144 | 1268 | Kimi K2.6 |
| Design Arena: agents building full-stack apps | 1054 | 1155 | Kimi K2.6 |
| Design Arena: agents building mobile apps | 1090 | 1157 | Kimi K2.6 |
| Design Arena: agents building Android apps | 1052 | 1160 | Kimi K2.6 |
| Design Arena: agents building Godot games | 1089 | 1120 | Kimi K2.6 |
| Design Arena: agents building games | Not measured | 1141 | Only Kimi K2.6 measured |
| Design Arena: HTML slides | 1180 | 1184 | Kimi K2.6 |
| Design Arena: PowerPoint slides | Not measured | 1128 | Only Kimi K2.6 measured |
| Design Arena: spreadsheets | Not measured | 1276 | Only Kimi K2.6 measured |
| Finance Agent (Vals AI) | 28.5% | 44.9% | Kimi K2.6 |
| Tax Agent Bench (Vals AI) | 7.0% | 12.4% | Kimi K2.6 |
| Legal Research Bench (Vals AI) | 13.9% | 15.9% | Kimi K2.6 |
| Excel Modeling Benchmark (Vals AI) | 11.7% | 57.9% | Kimi K2.6 |
| τ²-Bench Telecom | 93.0% | 95.9% | Kimi K2.6 |
| OSWorld 2.0 | Not measured | 4.6% | Only Kimi K2.6 measured |
| Vending-Bench 2 | $4,663 | $6,205 | Kimi K2.6 |
| Neither model has a result on the other 24 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| GPQA Diamond | 88.6% | 89.1% | Kimi K2.6 |
| MMMU Pro (Vals AI) | 83.5% | 86.3% | Kimi K2.6 |
| GPQA Diamond (Artificial Analysis run) | 91.1% | 91.1% | Tie |
| Humanity's Last Exam (Artificial Analysis run) | 34.5% | 37.5% | Kimi K2.6 |
| GPQA Diamond (Epoch AI run) | Not measured | 90.8% | Only Kimi K2.6 measured |
| ARC-AGI | 89.5% | Not measured | Only Grok 4.20 measured |
| ARC-AGI-2 | 65.1% | Not measured | Only Grok 4.20 measured |
| Chess puzzles | Not measured | 20.0% | Only Kimi K2.6 measured |
| Mystery game puzzles | Not measured | 18.0% | Only Kimi K2.6 measured |
| EBR-bench | Not measured | 2.4% | Only Kimi K2.6 measured |
| LMArena Text: hard prompts | Not measured | 1470 | Only Kimi K2.6 measured |
| LMArena Text: expert | Not measured | 1491 | Only Kimi K2.6 measured |
| LMArena Text: hard prompts in English | Not measured | 1471 | Only Kimi K2.6 measured |
| LMArena Vision: diagrams | Not measured | 1298 | Only Kimi K2.6 measured |
| LMArena Vision: homework | Not measured | 1310 | Only Kimi K2.6 measured |
| Kagi LLM Benchmark | 75.0% | Not measured | Only Grok 4.20 measured |
| Neither model has a result on the other 6 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| AIME | 96.5% | Not measured | Only Grok 4.20 measured |
| OTIS Mock AIME | Not measured | 96.1% | Only Kimi K2.6 measured |
| FrontierMath, tiers 1 to 3 | Not measured | 57.2% | Only Kimi K2.6 measured |
| FrontierMath, tier 4 | Not measured | 25.6% | Only Kimi K2.6 measured |
| ProofBench | Not measured | 16.0% | Only Kimi K2.6 measured |
| LMArena Text: math | Not measured | 1474 | Only Kimi K2.6 measured |
| LMArena Text: mathematical work | Not measured | 1480 | Only Kimi K2.6 measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index07
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| MMLU Pro | 86.3% | 87.6% | Kimi K2.6 |
| LegalBench (Vals AI) | 77.7% | 84.7% | Kimi K2.6 |
| CaseLaw (Vals AI) | 54.4% | 61.2% | Kimi K2.6 |
| CorpFin (Vals AI) | 63.7% | 66.7% | Kimi K2.6 |
| TaxEval (Vals AI) | 74.1% | 74.7% | Kimi K2.6 |
| MortgageTax (Vals AI) | 45.4% | 65.8% | Kimi K2.6 |
| MedQA (Vals AI) | 94.5% | Not measured | Only Grok 4.20 measured |
| MedCode (Vals AI) | 32.2% | 40.1% | Kimi K2.6 |
| SimpleQA Verified | Not measured | 34.9% | Only Kimi K2.6 measured |
| LMArena Text: science | Not measured | 1468 | Only Kimi K2.6 measured |
| LMArena Text: medicine and healthcare | Not measured | 1457 | Only Kimi K2.6 measured |
| LMArena Text: legal and government | Not measured | 1462 | Only Kimi K2.6 measured |
| LMArena Text: business and finance | Not measured | 1445 | Only Kimi K2.6 measured |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index17
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| Design Arena: websites | 1229 | 1269 | Kimi K2.6 |
| Design Arena: UI components | 1199 | 1266 | Kimi K2.6 |
| Design Arena: game dev | 1192 | 1251 | Kimi K2.6 |
| Design Arena: data viz | 1217 | 1249 | Kimi K2.6 |
| Design Arena: 3D | 1193 | 1268 | Kimi K2.6 |
| Design Arena: all code categories | 1221 | 1272 | Kimi K2.6 |
| Design Arena: SVG | 1164 | 1181 | Kimi K2.6 |
| Design Arena: ASCII art | 1174 | 1165 | Grok 4.20 |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index25
| Benchmark | Grok 4.20 | Kimi K2.6 | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | Not measured | 56.6% | Only Kimi K2.6 measured |
| SAGE (Vals AI) | 38.2% | 50.2% | Kimi K2.6 |
| MedScribe (Vals AI) | 63.4% | 78.2% | Kimi K2.6 |
| Vals Multimodal Index | 39.1% | 56.4% | Kimi K2.6 |
| IFBench | 81.2% | 76.0% | Grok 4.20 |
| Long context reasoning (AA-LCR) | 69.0% | 81.0% | Kimi K2.6 |
| DTBench | 90.1% | 90.9% | Kimi K2.6 |
| LMCA | 38.7% | 37.3% | Grok 4.20 |
| CL-bench | 22.2% | Not measured | Only Grok 4.20 measured |
| Furniture assembly | Not measured | 21.7% | Only Kimi K2.6 measured |
| ExploitBench | Not measured | 18.4% | Only Kimi K2.6 measured |
| CL-bench Life | 11.9% | Not measured | Only Grok 4.20 measured |
| LMArena Text | Not measured | 1455 | Only Kimi K2.6 measured |
| LMArena Text: instruction following | Not measured | 1451 | Only Kimi K2.6 measured |
| LMArena Text: creative writing | Not measured | 1434 | Only Kimi K2.6 measured |
| LMArena Vision | Not measured | 1282 | Only Kimi K2.6 measured |
| LMArena Text: English | Not measured | 1460 | Only Kimi K2.6 measured |
| LMArena Text: non-English | Not measured | 1446 | Only Kimi K2.6 measured |
| LMArena Text: Chinese | Not measured | 1520 | Only Kimi K2.6 measured |
| LMArena Text: German | Not measured | 1451 | Only Kimi K2.6 measured |
| LMArena Text: Japanese | Not measured | 1443 | Only Kimi K2.6 measured |
| LMArena Text: Korean | Not measured | 1427 | Only Kimi K2.6 measured |
| LMArena Text: French | Not measured | 1471 | Only Kimi K2.6 measured |
| LMArena Text: Spanish | Not measured | 1464 | Only Kimi K2.6 measured |
| LMArena Text: Russian | Not measured | 1446 | Only Kimi K2.6 measured |
| LMArena Text: Polish | Not measured | 1438 | Only Kimi K2.6 measured |
| LMArena Text: multi-turn | Not measured | 1453 | Only Kimi K2.6 measured |
| LMArena Text: longer queries | Not measured | 1468 | Only Kimi K2.6 measured |
| LMArena Text: writing and language | Not measured | 1439 | Only Kimi K2.6 measured |
| LMArena Text: entertainment and media | Not measured | 1428 | Only Kimi K2.6 measured |
| LMArena Vision: English | Not measured | 1287 | Only Kimi K2.6 measured |
| LMArena Vision: Chinese | Not measured | 1346 | Only Kimi K2.6 measured |
| LMArena Vision: reading text | Not measured | 1291 | Only Kimi K2.6 measured |
| LMArena Vision: humor | Not measured | 1280 | Only Kimi K2.6 measured |
| LMArena Vision: creative writing | Not measured | 1273 | Only Kimi K2.6 measured |
| LMArena Document | Not measured | 1451 | Only Kimi K2.6 measured |
| Neither model has a result on the other 10 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Grok 4.20 | Kimi K2.6 | 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
Kimi K2.6 costs less
Agent loop
200K input + 10K output tokens
Kimi K2.6 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 | MoonshotAI Kimi K2.6 |
|---|---|---|
| Maker | xAI | Moonshot AI |
| Weights | No public weights listed | Open weights |
| Released | March 31, 2026 | April 20, 2026 |
| Context window | 2M | 262K |
| Input $/Mtok | $1.25 | $0.95 |
| Output $/Mtok | $2.50 | $4.00 |
| Coding index | 33.3 | 52.1 |
| Independent measurements behind it | 2 | 3 |
| Cost per solved task | $0.72 | $0.35 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Grok 4.20 better than Kimi K2.6 for coding?
Pick Kimi K2.6 for coding: it scores 52.1 on the Vibe Coding Index against 33.3 for Grok 4.20. Pick Grok 4.20 for output tokens 1.6x cheaper ($2.50 vs $4.00 per million) and a larger context window (2M against 262K tokens).
Which is cheaper, Grok 4.20 or Kimi K2.6?
Grok 4.20 costs $1.25 per million input tokens and $2.50 per million output tokens; Kimi K2.6 costs $0.95 and $4.00. Per solved SWE-bench Verified task, Grok 4.20 costs $0.72 and Kimi K2.6 $0.35.
Which has the bigger context window, Grok 4.20 or Kimi K2.6?
Grok 4.20, with 2M tokens against 262K.
How many benchmarks is the Grok 4.20 vs Kimi K2.6 comparison based on?
47 benchmarks have a result for both models as of October 21, 2026. Grok 4.20's coding index rests on 2 independent benchmarks and Kimi K2.6's on 3. Where only one model has a result, the page says so instead of naming a winner.