Claude Opus 4.1 vs Grok 4.20
Grok 4.20 leads Claude Opus 4.1 on the Artificial Analysis Intelligence Index, 25.7 to 22.8, and Grok 4.20 costs 30.0x less per output token ($2.50 vs $75.00 per million). Updated October 21, 2026; 26 benchmarks have a result for both.
Claude Opus 4.1 or Grok 4.20: which to pick
Only Grok 4.20 has a coding score, 33.3 on the Vibe Coding Index; Claude Opus 4.1 has none, so the two cannot be ranked on coding.
Pick Claude Opus 4.1 for work measured by MMLU Pro or LegalBench (Vals AI), where it leads.
- Shared results
- 26
- Claude Opus 4.1 only
- 47
- Grok 4.20 only
- 29
- 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
Only Grok 4.20 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Grok 4.20
Grok 4.20 leads, 25.7 against 22.8.
Same board, both measured
Reasoning
GPQA Diamond
Grok 4.20
Grok 4.20 leads, 88.6% against 76.3%.
Same board, both measured
Math
AIME
Grok 4.20
Grok 4.20 leads, 96.5% against 78.2%.
Same board, both measured
Knowledge
MMLU Pro
Claude Opus 4.1
Claude Opus 4.1 leads, 87.9% against 86.3%.
Same board, both measured
Web design
Design Arena: websites
Grok 4.20
Grok 4.20 leads, 1229 against 1177.
Same board, both measured
Long documents
Listed context window
Grok 4.20
Grok 4.20 takes 2M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Grok 4.20
Claude Opus 4.1 $0.052, Grok 4.20 $0.0025 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Grok 4.20 has the number, $0.72.
Directional only
At a glance
- Coding index
- Claude Opus 4.1 not benchmarked, Grok 4.20 33.3 from 2 benchmarks.
- Widest category
- Math, 18.3 points apart on average over 1 shared benchmark.
- Widest single gap
- Terminal-Bench: Claude Opus 4.1 38.0% against Grok 4.20 57.3%, 19.3 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.1 $75.00 against Grok 4.20 $2.50 per million output tokens, 30.0x apart.
- Context window
- Claude Opus 4.1 takes 200K tokens, Grok 4.20 2M.
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 | Claude Opus 4.1 | Bars | Grok 4.20 | Ties |
|---|---|---|---|---|
| Coding | 0 | 3 | ||
| Intelligence | 0 | 2 | ||
| Reasoning | 0 | 2 | ||
| Math | 0 | 1 | ||
| Knowledge | 4 | 2 | ||
| Web design | 0 | 8 | ||
| General | 1 | 3 | ||
| All shared boards | 5 | 21 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index03
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| LMArena WebDev | 1390 | Not measured | Only Claude Opus 4.1 measured |
| LiveCodeBench (Vals AI) | 66.5% | 84.3% | Grok 4.20 |
| SWE-bench Verified (Vals AI) | Not measured | 72.2% | Only Grok 4.20 measured |
| Vibe Code Bench (Vals AI) | Not measured | 4.1% | Only Grok 4.20 measured |
| Code migration (Vals AI) | Not measured | 0.3% | Only Grok 4.20 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 44.2% | Only Grok 4.20 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 37.9% | Only Grok 4.20 measured |
| Terminal-Bench | 38.0% | 57.3% | Grok 4.20 |
| WeirdML | 45.9% | 52.3% | Grok 4.20 |
| Cybench | 42.0% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: coding | 1479 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: software and IT | 1456 | Not measured | Only Claude Opus 4.1 measured |
| LMArena WebDev: HTML | 1399 | Not measured | Only Claude Opus 4.1 measured |
| SciCode | 4.6% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 25 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| AA Intelligence Index | 22.8 | 25.7 | Grok 4.20 |
| Epoch Capabilities Index | 144.1 | 152.1 | Grok 4.20 |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index15 boards, none shared
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1144 | Only Grok 4.20 measured |
| Design Arena: agents building full-stack apps | Not measured | 1054 | Only Grok 4.20 measured |
| Design Arena: agents building mobile apps | Not measured | 1090 | Only Grok 4.20 measured |
| Design Arena: agents building Android apps | Not measured | 1052 | Only Grok 4.20 measured |
| Design Arena: agents building Godot games | Not measured | 1089 | Only Grok 4.20 measured |
| Design Arena: HTML slides | Not measured | 1180 | Only Grok 4.20 measured |
| Finance Agent (Vals AI) | Not measured | 28.5% | Only Grok 4.20 measured |
| Tax Agent Bench (Vals AI) | Not measured | 7.0% | Only Grok 4.20 measured |
| Legal Research Bench (Vals AI) | Not measured | 13.9% | Only Grok 4.20 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 11.7% | Only Grok 4.20 measured |
| τ²-Bench Telecom | Not measured | 93.0% | Only Grok 4.20 measured |
| METR time horizons | 66.8% | Not measured | Only Claude Opus 4.1 measured |
| GDPval | 43.6% | Not measured | Only Claude Opus 4.1 measured |
| DeepResearch Bench | 48.3% | Not measured | Only Claude Opus 4.1 measured |
| Vending-Bench 2 | Not measured | $4,663 | Only Grok 4.20 measured |
| Neither model has a result on the other 26 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| GPQA Diamond | 76.3% | 88.6% | Grok 4.20 |
| MMMU Pro (Vals AI) | 77.5% | 83.5% | Grok 4.20 |
| GPQA Diamond (Artificial Analysis run) | Not measured | 91.1% | Only Grok 4.20 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 34.5% | Only Grok 4.20 measured |
| GPQA Diamond (Epoch AI run) | 77.3% | Not measured | Only Claude Opus 4.1 measured |
| ARC-AGI | Not measured | 89.5% | Only Grok 4.20 measured |
| ARC-AGI-2 | Not measured | 65.1% | Only Grok 4.20 measured |
| SimpleBench | 60.0% | Not measured | Only Claude Opus 4.1 measured |
| Mystery game puzzles | 21.0% | Not measured | Only Claude Opus 4.1 measured |
| EBR-bench | 7.9% | Not measured | Only Claude Opus 4.1 measured |
| VPCT | 35.0% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: hard prompts | 1442 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: expert | 1438 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: hard prompts in English | 1451 | Not measured | Only Claude Opus 4.1 measured |
| Kagi LLM Benchmark | Not measured | 75.0% | Only Grok 4.20 measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| AIME | 78.2% | 96.5% | Grok 4.20 |
| MATH 500 (Vals AI) | 95.4% | Not measured | Only Claude Opus 4.1 measured |
| MGSM (Vals AI) | 94.4% | Not measured | Only Claude Opus 4.1 measured |
| OTIS Mock AIME | 68.9% | Not measured | Only Claude Opus 4.1 measured |
| FrontierMath, tiers 1 to 3 | 12.6% | Not measured | Only Claude Opus 4.1 measured |
| FrontierMath, tier 4 | 2.4% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: math | 1431 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: mathematical work | 1434 | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 5 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index42
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| MMLU Pro | 87.9% | 86.3% | Claude Opus 4.1 |
| LegalBench (Vals AI) | 83.5% | 77.7% | Claude Opus 4.1 |
| CaseLaw (Vals AI) | Not measured | 54.4% | Only Grok 4.20 measured |
| CorpFin (Vals AI) | Not measured | 63.7% | Only Grok 4.20 measured |
| TaxEval (Vals AI) | 73.7% | 74.1% | Grok 4.20 |
| MortgageTax (Vals AI) | 61.1% | 45.4% | Claude Opus 4.1 |
| MedQA (Vals AI) | 93.6% | 94.5% | Grok 4.20 |
| MedCode (Vals AI) | 47.2% | 32.2% | Claude Opus 4.1 |
| LMArena Text: science | 1422 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: medicine and healthcare | 1416 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: legal and government | 1421 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: business and finance | 1406 | Not measured | Only Claude Opus 4.1 measured |
| FACTS Benchmark Suite | 40.4% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| Design Arena: websites | 1177 | 1229 | Grok 4.20 |
| Design Arena: UI components | 1165 | 1199 | Grok 4.20 |
| Design Arena: game dev | 1171 | 1192 | Grok 4.20 |
| Design Arena: data viz | 1166 | 1217 | Grok 4.20 |
| Design Arena: 3D | 1153 | 1193 | Grok 4.20 |
| Design Arena: all code categories | 1171 | 1221 | Grok 4.20 |
| Design Arena: SVG | 1152 | 1164 | Grok 4.20 |
| Design Arena: ASCII art | 1167 | 1174 | 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 index13
| Benchmark | Claude Opus 4.1 | Grok 4.20 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 31.4% | 38.2% | Grok 4.20 |
| MedScribe (Vals AI) | 73.9% | 63.4% | Claude Opus 4.1 |
| Vals Multimodal Index | Not measured | 39.1% | Only Grok 4.20 measured |
| IFBench | Not measured | 81.2% | Only Grok 4.20 measured |
| Long context reasoning (AA-LCR) | Not measured | 69.0% | Only Grok 4.20 measured |
| DTBench | 80.0% | 90.1% | Grok 4.20 |
| LMCA | 37.1% | 38.7% | Grok 4.20 |
| Creative writing (Lech Mazur) | 84.7% | Not measured | Only Claude Opus 4.1 measured |
| CL-bench | Not measured | 22.2% | Only Grok 4.20 measured |
| CL-bench Life | Not measured | 11.9% | Only Grok 4.20 measured |
| LMArena Text | 1419 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: instruction following | 1435 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: creative writing | 1412 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: English | 1433 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: non-English | 1405 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Chinese | 1427 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: German | 1413 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Japanese | 1377 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Korean | 1381 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: French | 1433 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Spanish | 1448 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Russian | 1422 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Polish | 1413 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: multi-turn | 1444 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: longer queries | 1455 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: writing and language | 1418 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: entertainment and media | 1398 | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.1 | Grok 4.20 | 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
Grok 4.20 costs less
Agent loop
200K input + 10K output tokens
Grok 4.20 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 | Anthropic Claude Opus 4.1 | SpaceXAI Grok 4.20 |
|---|---|---|
| Maker | Anthropic | xAI |
| Weights | No public weights listed | No public weights listed |
| Released | August 5, 2025 | March 31, 2026 |
| Context window | 200K | 2M |
| Input $/Mtok | $15.00 | $1.25 |
| Output $/Mtok | $75.00 | $2.50 |
| Coding index | Not benchmarked | 33.3 |
| Independent measurements behind it | 1 | 2 |
| Cost per solved task | Not computable | $0.72 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.1 better than Grok 4.20 for coding?
Only Grok 4.20 has a coding score, 33.3 on the Vibe Coding Index; Claude Opus 4.1 has none, so the two cannot be ranked on coding. Pick Claude Opus 4.1 for work measured by MMLU Pro or LegalBench (Vals AI), where it leads.
Which is cheaper, Claude Opus 4.1 or Grok 4.20?
Claude Opus 4.1 costs $15.00 per million input tokens and $75.00 per million output tokens; Grok 4.20 costs $1.25 and $2.50. Cost per solved task is known for Grok 4.20 only.
Which has the bigger context window, Claude Opus 4.1 or Grok 4.20?
Grok 4.20, with 2M tokens against 200K.
How many benchmarks is the Claude Opus 4.1 vs Grok 4.20 comparison based on?
26 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.1's coding index rests on 1 independent benchmark and Grok 4.20's on 2. Where only one model has a result, the page says so instead of naming a winner.