# Devstral Small 2505 vs Grok 4.1 Fast

> Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 34.3 on the Noometry Index. Devstral Small 2505 costs 1.8× less per token, which makes it the better buy when Grok 4.1 Fast's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/devstral-small-vs-grok-4-1-fast
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 19.7.
- Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $0.20 / $0.50 for Grok 4.1 Fast.
- Devstral Small 2505 has downloadable open weights; the other is API-only.

## Snapshot

| | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| Provider | Mistral AI | xAI |
| Noometry Index | 34.3 | 41.4 |
| Rank | 233 | 136 |
| Context | 128K | 128K |
| Input $/M | $0.10 | $0.20 |
| Output $/M | $0.30 | $0.50 |
| Weights | Open | Proprietary |

## Coding

- Devstral Small 2505: 38.9 (#166)
- Grok 4.1 Fast: 34.1 (#245)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| LMArena WebDev | — | 1242 |
| SciCode | 28.8% | — |
| LMArena Coding | — | 1411 |
| ALE-Bench | — | 394.93 |

## Agentic & Tool Use

- Devstral Small 2505: —
- Grok 4.1 Fast: 36.3 (#39)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | — | 1,107 |

## Reasoning

- Devstral Small 2505: 19.7 (#252)
- Grok 4.1 Fast: 43.4 (#49)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| SimpleBench | — | 56% |
| Kagi LLM Benchmark | 37.7% | — |
| NYT Connections (extended) | — | 87.4% |
| CritPt | 0% | — |
| LMArena Hard Prompts | — | 1407 |
| DTBench | — | 87.7% |
| ForecastBench | — | 61 |

## Math

- Devstral Small 2505: —
- Grok 4.1 Fast: 31.9 (#221)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| MathArena Final-Answer Competitions | — | 60.9% |
| ProofBench | — | 4% |
| LMArena Math | — | 1408 |

## Knowledge

- Devstral Small 2505: —
- Grok 4.1 Fast: 33.1 (#207)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| Vectara Hallucination Rate | — | 17.8% |
| LMArena Expert | — | 1399 |

## Multimodal

- Devstral Small 2505: —
- Grok 4.1 Fast: 37.0 (#76)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |

## Multilingual

- Devstral Small 2505: —
- Grok 4.1 Fast: 51.0 (#114)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | — | 1391 |
| LMArena Chinese | — | 1441 |
| LMArena French | — | 1415 |
| LMArena German | — | 1404 |
| LMArena Japanese | — | 1349 |
| LMArena Korean | — | 1361 |
| LMArena Russian | — | 1387 |
| LMArena Spanish | — | 1413 |

## Instruction Following

- Devstral Small 2505: —
- Grok 4.1 Fast: 72.7 (#133)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | — | 1376 |

## Long Context

- Devstral Small 2505: —
- Grok 4.1 Fast: 42.4 (#126)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | — | 1390 |

## Writing & Preference

- Devstral Small 2505: —
- Grok 4.1 Fast: 57.2 (#131)

| Benchmark | Devstral Small 2505 | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | — | 1408 |
| LMArena Creative Writing | — | 1394 |
| EQ-Bench Creative Writing | — | 1327 |
| LMArena Multi-Turn | — | 1389 |

## FAQ

### Is Devstral Small 2505 better than Grok 4.1 Fast?

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 34.3 on the Noometry Index. Devstral Small 2505 costs 1.8× less per token, which makes it the better buy when Grok 4.1 Fast's lead doesn't matter for your workload.

### Which is cheaper, Devstral Small 2505 or Grok 4.1 Fast?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Grok 4.1 Fast lists at $0.20 and $0.50.

### Is Devstral Small 2505 or Grok 4.1 Fast better for coding?

Devstral Small 2505 scores higher on coding benchmarks: 38.9 versus 34.1 in the Noometry coding category.

### Which has the bigger context window?

Both accept 128K tokens.

### How many benchmarks do Devstral Small 2505 and Grok 4.1 Fast share?

0 benchmarks have published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Grok 4.1 Fast has 32.