# DeepSeek V4 Flash vs Grok 4.1 Fast

> DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 41.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/deepseek-v4-flash-vs-grok-4-1-fast
- Last updated: 2026-10-10
- Shared benchmarks: 25

## Summary

- They share 25 benchmarks with published results for both. DeepSeek V4 Flash scores higher in 8 categories and Grok 4.1 Fast in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where DeepSeek V4 Flash leads 60.3 to 31.9.
- The biggest single-benchmark swing is ProofBench: 56% for DeepSeek V4 Flash and 4% for Grok 4.1 Fast.
- Both cost about the same: $0.15 input and $0.60 output per million tokens.
- DeepSeek V4 Flash accepts more context: 1M tokens versus 128K.
- DeepSeek V4 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| Provider | DeepSeek | xAI |
| Noometry Index | 53.6 | 41.4 |
| Rank | 35 | 136 |
| Context | 1M | 128K |
| Input $/M | $0.15 | $0.20 |
| Output $/M | $0.60 | $0.50 |
| Weights | Open | Proprietary |

## Coding

- DeepSeek V4 Flash: 47.9 (#59)
- Grok 4.1 Fast: 34.1 (#245)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena WebDev | 1582 | 1242 |
| LMArena Coding | 1457 | 1411 |
| ALE-Bench | 1,306 | 394.93 |
| FrontierCode | 18.8% | — |
| SciCode | 49.9% | — |
| WeirdML | 63% | — |

## Agentic & Tool Use

- DeepSeek V4 Flash: —
- Grok 4.1 Fast: 36.3 (#39)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | — | 1,107 |

## Reasoning

- DeepSeek V4 Flash: 53.7 (#30)
- Grok 4.1 Fast: 43.4 (#49)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | 61.1% | 56% |
| NYT Connections (extended) | 89.6% | 87.4% |
| LMArena Hard Prompts | 1444 | 1407 |
| DTBench | 90.9% | 87.7% |
| ARC-AGI-2 | 61.4% | — |
| Kagi LLM Benchmark | 52.2% | — |
| ARC-AGI-1 | 89% | — |
| CritPt | 16.6% | — |
| Chess Puzzles | 33% | — |
| Mystery Game Puzzles | 34% | — |
| LMCA | 41.7% | — |
| Epoch Capabilities Index | 154.49 | — |
| ForecastBench | — | 61 |

## Math

- DeepSeek V4 Flash: 60.3 (#37)
- Grok 4.1 Fast: 31.9 (#221)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| MathArena Final-Answer Competitions | 76.5% | 60.9% |
| ProofBench | 56% | 4% |
| LMArena Math | 1427 | 1408 |
| FrontierMath (Tiers 1-3) | 57.5% | — |
| FrontierMath Tier 4 | 24.4% | — |
| OTIS Mock AIME 2024-2025 | 94.4% | — |

## Knowledge

- DeepSeek V4 Flash: 55.4 (#48)
- Grok 4.1 Fast: 33.1 (#207)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena Expert | 1441 | 1399 |
| GPQA Diamond | 91% | — |
| SimpleQA Verified | 33.6% | — |
| Vectara Hallucination Rate | — | 17.8% |

## Multimodal

- DeepSeek V4 Flash: —
- Grok 4.1 Fast: 37.0 (#76)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |

## Multilingual

- DeepSeek V4 Flash: 53.0 (#72)
- Grok 4.1 Fast: 51.0 (#114)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1420 | 1391 |
| LMArena Chinese | 1468 | 1441 |
| LMArena French | 1439 | 1415 |
| LMArena German | 1418 | 1404 |
| LMArena Japanese | 1406 | 1349 |
| LMArena Korean | 1384 | 1361 |
| LMArena Russian | 1428 | 1387 |
| LMArena Spanish | 1436 | 1413 |

## Instruction Following

- DeepSeek V4 Flash: 74.9 (#81)
- Grok 4.1 Fast: 72.7 (#133)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1421 | 1376 |

## Long Context

- DeepSeek V4 Flash: 43.8 (#85)
- Grok 4.1 Fast: 42.4 (#126)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1434 | 1390 |

## Writing & Preference

- DeepSeek V4 Flash: 63.8 (#61)
- Grok 4.1 Fast: 57.2 (#131)

| Benchmark | DeepSeek V4 Flash | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1432 | 1408 |
| LMArena Creative Writing | 1403 | 1394 |
| EQ-Bench Creative Writing | 1559 | 1327 |
| LMArena Multi-Turn | 1449 | 1389 |

## FAQ

### Is DeepSeek V4 Flash better than Grok 4.1 Fast?

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 41.4 on the Noometry Index.

### Which is cheaper, DeepSeek V4 Flash or Grok 4.1 Fast?

DeepSeek V4 Flash is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Grok 4.1 Fast lists at $0.20 and $0.50.

### Is DeepSeek V4 Flash or Grok 4.1 Fast better for coding?

DeepSeek V4 Flash scores higher on coding benchmarks: 47.9 versus 34.1 in the Noometry coding category.

### Which has the bigger context window?

DeepSeek V4 Flash does, with 1M tokens against 128K.

### How many benchmarks do DeepSeek V4 Flash and Grok 4.1 Fast share?

25 benchmarks have published results for both models. DeepSeek V4 Flash has 41 scored results on Noometry and Grok 4.1 Fast has 32.