# GPT-4 vs Grok 4.1 Fast

> Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 28.9 on the Noometry Index.

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

## Summary

- They share 20 benchmarks with published results for both. GPT-4 scores higher in 0 categories and Grok 4.1 Fast in 8 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 42.3 to 17.3.
- The biggest single-benchmark swing is DTBench: 62.7% for GPT-4 and 87.7% for Grok 4.1 Fast.
- Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $30 / $60 for GPT-4.
- Grok 4.1 Fast accepts more context: 128K tokens versus 8K.

## Snapshot

| | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 28.9 | 40.9 |
| Rank | 308 | 131 |
| Context | 8K | 128K |
| Input $/M | $30 | $0.20 |
| Output $/M | $60 | $0.50 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-4: 31.2 (#277)
- Grok 4.1 Fast: 33.8 (#236)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Coding | 1254 | 1411 |
| LMArena WebDev | — | 1241 |
| WeirdML | 12.4% | — |
| BigCodeBench Instruct | 46% | — |
| BigCodeBench Complete | 57.2% | — |
| ALE-Bench | — | 394.93 |
| HumanEval+ | 79.3% | — |

## Agentic & Tool Use

- GPT-4: —
- Grok 4.1 Fast: 36.1 (#35)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| LMArena Search | — | 1171 |
| METR Time Horizons | 36.1% | — |
| Vending-Bench 2 | — | 1,107 |

## Reasoning

- GPT-4: 17.3 (#285)
- Grok 4.1 Fast: 42.3 (#45)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Hard Prompts | 1241 | 1407 |
| DTBench | 62.7% | 87.7% |
| ForecastBench | 57.8 | 61 |
| SimpleBench | — | 56% |
| NYT Connections (extended) | — | 87.4% |
| Chess Puzzles | 4% | — |
| Mystery Game Puzzles | 12% | — |
| LMCA | 17.1% | — |
| BIG-Bench Hard | 75.1% | — |
| Epoch Capabilities Index | 125.88 | — |
| HellaSwag | 95.3% | — |
| WinoGrande | 87.5% | — |

## Math

- GPT-4: 10.1 (#304)
- Grok 4.1 Fast: 30.9 (#201)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Math | 1269 | 1408 |
| MathArena Final-Answer Competitions | — | 60.9% |
| OTIS Mock AIME 2024-2025 | 1.1% | — |
| ProofBench | — | 4% |
| MATH Level 5 | 23% | — |
| GSM8K | 92% | — |

## Knowledge

- GPT-4: 18.4 (#277)
- Grok 4.1 Fast: 32.6 (#203)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Expert | 1211 | 1398 |
| GPQA Diamond | 35.7% | — |
| Vectara Hallucination Rate | — | 17.8% |
| MMLU | 86.4% | — |
| TriviaQA | 84.8% | — |

## Multimodal

- GPT-4: —
- Grok 4.1 Fast: 36.3 (#71)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |

## Multilingual

- GPT-4: 40.8 (#210)
- Grok 4.1 Fast: 51.1 (#110)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1246 | 1391 |
| LMArena Chinese | 1242 | 1441 |
| LMArena French | 1282 | 1416 |
| LMArena German | 1251 | 1404 |
| LMArena Japanese | 1209 | 1347 |
| LMArena Korean | 1184 | 1361 |
| LMArena Russian | 1251 | 1387 |
| LMArena Spanish | 1261 | 1411 |

## Instruction Following

- GPT-4: 65.5 (#217)
- Grok 4.1 Fast: 72.8 (#127)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1241 | 1376 |

## Long Context

- GPT-4: 37.7 (#207)
- Grok 4.1 Fast: 42.4 (#121)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1244 | 1390 |

## Writing & Preference

- GPT-4: 35.0 (#263)
- Grok 4.1 Fast: 57.4 (#126)

| Benchmark | GPT-4 | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1263 | 1408 |
| LMArena Creative Writing | 1244 | 1394 |
| EQ-Bench Creative Writing | 752 | 1327 |
| LMArena Multi-Turn | 1257 | 1389 |

## FAQ

### Is GPT-4 better than Grok 4.1 Fast?

Grok 4.1 Fast is the stronger model overall, scoring 40.9 to 28.9 on the Noometry Index.

### Which is cheaper, GPT-4 or Grok 4.1 Fast?

Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; GPT-4 lists at $30 and $60.

### Is GPT-4 or Grok 4.1 Fast better for coding?

Grok 4.1 Fast scores higher on coding benchmarks: 33.8 versus 31.2 in the Noometry coding category.

### Which has the bigger context window?

Grok 4.1 Fast does, with 128K tokens against 8K.

### How many benchmarks do GPT-4 and Grok 4.1 Fast share?

20 benchmarks have published results for both models. GPT-4 has 38 scored results on Noometry and Grok 4.1 Fast has 32.