# GPT-5.1 vs Grok 4.20 (Non-Reasoning)

> GPT-5.1 and Grok 4.20 (Non-Reasoning) score almost the same on the Noometry Index (49.0 vs 48.6), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gpt-5-1-vs-grok-4-20
- Last updated: 2026-10-10
- Shared benchmarks: 37

## Summary

- They share 37 benchmarks with published results for both. GPT-5.1 scores higher in 5 categories and Grok 4.20 (Non-Reasoning) in 5 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.20 (Non-Reasoning) leads 52.3 to 39.8.
- The biggest single-benchmark swing is ARC-AGI-2: 17.6% for GPT-5.1 and 65.1% for Grok 4.20 (Non-Reasoning).
- Grok 4.20 (Non-Reasoning) is cheaper at $1.25 / $2.50 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
- Grok 4.20 (Non-Reasoning) accepts more context: 1M tokens versus 400K.

## Snapshot

| | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 49.0 | 48.6 |
| Rank | 53 | 54 |
| Context | 400K | 1M |
| Input $/M | $1.25 | $1.25 |
| Output $/M | $10 | $2.50 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.1: 46.4 (#66)
- Grok 4.20 (Non-Reasoning): 42.1 (#112)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena WebDev | 1395 | 1375 |
| WeirdML | 60.8% | 52.3% |
| LMArena Coding | 1454 | 1459 |
| ALE-Bench | 1,192 | 1,150 |
| SWE-bench Verified | 68% | — |
| SWE-bench Verified (bash only) | 66% | — |
| SciCode | 43.3% | — |
| GSO | 13.7% | — |
| LiveBench Coding | 72.5% | — |

## Agentic & Tool Use

- GPT-5.1: 32.7 (#60)
- Grok 4.20 (Non-Reasoning): 34.4 (#46)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Terminal-Bench | 47.6% | 57.3% |
| LMArena Search | 1199 | 1189 |
| Vending-Bench 2 | 1,473 | 4,663 |
| τ²-bench Banking | — | 18% |
| DeepResearch Bench | 42.8% | — |

## Reasoning

- GPT-5.1: 39.8 (#58)
- Grok 4.20 (Non-Reasoning): 52.3 (#32)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| ARC-AGI-2 | 17.6% | 65.1% |
| ARC-AGI-1 | 72.8% | 89.5% |
| Chess Puzzles | 32% | 24% |
| LMArena Hard Prompts | 1457 | 1451 |
| DTBench | 90.1% | 90.1% |
| LMCA | 43.9% | 38.7% |
| Epoch Capabilities Index | 149.64 | 151.98 |
| ForecastBench | 58.1 | 61.4 |
| SimpleBench | 53.2% | — |
| Kagi LLM Benchmark | — | 75% |
| NYT Connections (extended) | — | 85.4% |
| CritPt | 4.9% | — |
| EnigmaEval | 11.2% | — |
| Thematic Generalization | — | 63.8% |
| LiveBench Reasoning | 95.8% | — |
| Mystery Game Puzzles | 19% | — |
| LiveBench Data Analysis | 72.1% | — |
| LiveBench | 78.8% | — |

## Math

- GPT-5.1: 52.2 (#51)
- Grok 4.20 (Non-Reasoning): 48.2 (#65)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 88.6% | 92.2% |
| LMArena Math | 1447 | 1455 |
| FrontierMath (Tiers 1-3) | — | 44.9% |
| FrontierMath Tier 4 | — | 17.1% |
| ProofBench | — | 14% |
| Omni-MATH | 46.4% | — |
| LiveBench Math | 94.5% | — |
| FrontierMath (Feb 2025 set) | 31% | — |
| FrontierMath Tier 4 (v1) | 12.5% | — |

## Knowledge

- GPT-5.1: 50.6 (#71)
- Grok 4.20 (Non-Reasoning): 52.8 (#60)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| GPQA Diamond | 87.6% | 89.3% |
| SimpleQA Verified | 48% | 30.2% |
| LMArena Expert | 1470 | 1439 |
| Humanity's Last Exam | 23.7% | — |
| MMLU-Pro | 57.9% | — |
| Vectara Hallucination Rate | 10.9% | — |
| GPQA (HELM) | 44.2% | — |

## Multimodal

- GPT-5.1: 44.8 (#19)
- Grok 4.20 (Non-Reasoning): 33.3 (#98)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Vision | 1250 | 1263 |
| LMArena Document | 1403 | 1416 |
| VPCT | 58.7% | — |
| Blueprint-Bench 2 | — | 0% |

## Multilingual

- GPT-5.1: 53.8 (#56)
- Grok 4.20 (Non-Reasoning): 54.5 (#40)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Non-English | 1431 | 1441 |
| LMArena Chinese | 1495 | 1481 |
| LMArena French | 1450 | 1476 |
| LMArena German | 1438 | 1465 |
| LMArena Japanese | 1453 | 1449 |
| LMArena Korean | 1401 | 1417 |
| LMArena Russian | 1435 | 1458 |
| LMArena Spanish | 1433 | 1443 |

## Instruction Following

- GPT-5.1: 83.9 (#1)
- Grok 4.20 (Non-Reasoning): 74.8 (#83)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Instruction Following | 1443 | 1420 |
| LiveBench Instruction Following | 93.3% | — |
| IFEval | 93.5% | — |

## Long Context

- GPT-5.1: 47.6 (#14)
- Grok 4.20 (Non-Reasoning): 45.5 (#34)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| CL-bench | 23.7% | 22.2% |
| CL-bench Life | 17.3% | 11.9% |
| LMArena Longer Query | 1447 | 1437 |

## Writing & Preference

- GPT-5.1: 64.5 (#55)
- Grok 4.20 (Non-Reasoning): 65.7 (#44)

| Benchmark | GPT-5.1 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Text | 1443 | 1451 |
| LMArena Creative Writing | 1427 | 1438 |
| LMArena Multi-Turn | 1450 | 1456 |
| EQ-Bench Creative Writing | — | 1574 |
| WildBench | 86.3% | — |
| LiveBench Language | 80.2% | — |

## FAQ

### Is GPT-5.1 better than Grok 4.20 (Non-Reasoning)?

GPT-5.1 and Grok 4.20 (Non-Reasoning) score almost the same on the Noometry Index (49.0 vs 48.6), so choose on price, context window or the category you care about most.

### Which is cheaper, GPT-5.1 or Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; GPT-5.1 lists at $1.25 and $10.

### Is GPT-5.1 or Grok 4.20 (Non-Reasoning) better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 42.1 in the Noometry coding category.

### Which has the bigger context window?

Grok 4.20 (Non-Reasoning) does, with 1M tokens against 400K.

### How many benchmarks do GPT-5.1 and Grok 4.20 (Non-Reasoning) share?

37 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.