# DeepSeek-V3.1 vs Grok 4 Fast

> DeepSeek-V3.1 is the stronger model overall, scoring 42.2 to 39.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/deepseek-v3-1-vs-grok-4-fast
- Last updated: 2026-10-10
- Shared benchmarks: 24

## Summary

- They share 24 benchmarks with published results for both. DeepSeek-V3.1 scores higher in 7 categories and Grok 4 Fast in 1 category; 4 gaps are clear of the uncertainty.
- The widest gap is in long context, where Grok 4 Fast leads 63.2 to 36.3.
- The biggest single-benchmark swing is Fiction.LiveBench: 52.8% for DeepSeek-V3.1 and 94.4% for Grok 4 Fast.
- DeepSeek-V3.1 has downloadable open weights; the other is API-only.

## Snapshot

| | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Provider | DeepSeek | xAI |
| Noometry Index | 42.2 | 39.0 |
| Rank | 106 | 164 |
| Context | 164K | — |
| Input $/M | $0.25 | — |
| Output $/M | $0.95 | — |
| Weights | Open | Proprietary |

## Coding

- DeepSeek-V3.1: 39.8 (#140)
- Grok 4 Fast: 32.3 (#264)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| WeirdML | 38.4% | 42.9% |
| LMArena Coding | 1417 | 1429 |
| LMArena WebDev | — | 1160 |

## Agentic & Tool Use

- DeepSeek-V3.1: —
- Grok 4 Fast: 29.3 (#80)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| τ²-bench Banking | — | 15.7% |
| Cybench | — | 30% |
| LMArena Search | — | 1171 |

## Reasoning

- DeepSeek-V3.1: 27.3 (#109)
- Grok 4 Fast: 22.5 (#179)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Kagi LLM Benchmark | 53.2% | 66.1% |
| LMArena Hard Prompts | 1417 | 1413 |
| DTBench | 82.7% | 82.7% |
| Epoch Capabilities Index | 139.92 | 144.21 |
| ForecastBench | 58 | 60.5 |
| ARC-AGI-2 | — | 5.3% |
| SimpleBench | 40% | — |
| ARC-AGI-1 | — | 48.5% |
| LMCA | 24.3% | — |

## Math

- DeepSeek-V3.1: 36.1 (#125)
- Grok 4 Fast: 36.1 (#126)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Math | 1420 | 1419 |

## Knowledge

- DeepSeek-V3.1: 43.0 (#86)
- Grok 4 Fast: 31.5 (#211)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Vectara Hallucination Rate | 5.5% | 19.7% |
| LMArena Expert | 1403 | 1411 |

## Multilingual

- DeepSeek-V3.1: 51.8 (#100)
- Grok 4 Fast: 51.5 (#106)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Non-English | 1400 | 1397 |
| LMArena Chinese | 1470 | 1458 |
| LMArena French | 1447 | 1433 |
| LMArena German | 1412 | 1383 |
| LMArena Japanese | 1374 | 1358 |
| LMArena Korean | 1337 | 1359 |
| LMArena Russian | 1405 | 1387 |
| LMArena Spanish | 1429 | 1414 |

## Instruction Following

- DeepSeek-V3.1: 74.1 (#105)
- Grok 4 Fast: 73.4 (#116)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Instruction Following | 1400 | 1388 |

## Long Context

- DeepSeek-V3.1: 36.3 (#227)
- Grok 4 Fast: 63.2 (#3)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| Fiction.LiveBench | 52.8% | 94.4% |
| LMArena Longer Query | 1422 | 1415 |

## Writing & Preference

- DeepSeek-V3.1: 60.5 (#93)
- Grok 4 Fast: 60.2 (#96)

| Benchmark | DeepSeek-V3.1 | Grok 4 Fast |
|---|---|---|
| LMArena Text | 1420 | 1407 |
| LMArena Creative Writing | 1401 | 1388 |
| LMArena Multi-Turn | 1408 | 1414 |
| EQ-Bench Creative Writing | 1436 | — |

## FAQ

### Is DeepSeek-V3.1 better than Grok 4 Fast?

DeepSeek-V3.1 is the stronger model overall, scoring 42.2 to 39.0 on the Noometry Index.

### Is DeepSeek-V3.1 or Grok 4 Fast better for coding?

DeepSeek-V3.1 scores higher on coding benchmarks: 39.8 versus 32.3 in the Noometry coding category.

### How many benchmarks do DeepSeek-V3.1 and Grok 4 Fast share?

24 benchmarks have published results for both models. DeepSeek-V3.1 has 27 scored results on Noometry and Grok 4 Fast has 30.