# Devstral Small 2505 vs Grok 4.20 (Non-Reasoning)

> Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 34.3 on the Noometry Index. Devstral Small 2505 costs 10× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

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

## Summary

- They share 1 benchmark with published results for both. Devstral Small 2505 scores higher in 0 categories and Grok 4.20 (Non-Reasoning) in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.20 (Non-Reasoning) leads 52.3 to 19.7.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 37.7% for Devstral Small 2505 and 75% for Grok 4.20 (Non-Reasoning).
- Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 (Non-Reasoning).
- Grok 4.20 (Non-Reasoning) accepts more context: 1M tokens versus 128K.
- Devstral Small 2505 has downloadable open weights; the other is API-only.

## Snapshot

| | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Provider | Mistral AI | xAI |
| Noometry Index | 34.3 | 48.6 |
| Rank | 233 | 54 |
| Context | 128K | 1M |
| Input $/M | $0.10 | $1.25 |
| Output $/M | $0.30 | $2.50 |
| Weights | Open | Proprietary |

## Coding

- Devstral Small 2505: 38.9 (#166)
- Grok 4.20 (Non-Reasoning): 42.1 (#112)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| LMArena WebDev | — | 1375 |
| SciCode | 28.8% | — |
| WeirdML | — | 52.3% |
| LMArena Coding | — | 1459 |
| ALE-Bench | — | 1,150 |

## Agentic & Tool Use

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 34.4 (#46)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Terminal-Bench | — | 57.3% |
| τ²-bench Banking | — | 18% |
| LMArena Search | — | 1189 |
| Vending-Bench 2 | — | 4,663 |

## Reasoning

- Devstral Small 2505: 19.7 (#252)
- Grok 4.20 (Non-Reasoning): 52.3 (#32)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | 75% |
| ARC-AGI-2 | — | 65.1% |
| NYT Connections (extended) | — | 85.4% |
| ARC-AGI-1 | — | 89.5% |
| CritPt | 0% | — |
| Chess Puzzles | — | 24% |
| Thematic Generalization | — | 63.8% |
| LMArena Hard Prompts | — | 1451 |
| DTBench | — | 90.1% |
| LMCA | — | 38.7% |
| Epoch Capabilities Index | — | 151.98 |
| ForecastBench | — | 61.4 |

## Math

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 48.2 (#65)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 44.9% |
| FrontierMath Tier 4 | — | 17.1% |
| OTIS Mock AIME 2024-2025 | — | 92.2% |
| ProofBench | — | 14% |
| LMArena Math | — | 1455 |

## Knowledge

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 52.8 (#60)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| GPQA Diamond | — | 89.3% |
| SimpleQA Verified | — | 30.2% |
| LMArena Expert | — | 1439 |

## Multimodal

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 33.3 (#98)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Vision | — | 1263 |
| Blueprint-Bench 2 | — | 0% |
| LMArena Document | — | 1416 |

## Multilingual

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 54.5 (#40)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Non-English | — | 1441 |
| LMArena Chinese | — | 1481 |
| LMArena French | — | 1476 |
| LMArena German | — | 1465 |
| LMArena Japanese | — | 1449 |
| LMArena Korean | — | 1417 |
| LMArena Russian | — | 1458 |
| LMArena Spanish | — | 1443 |

## Instruction Following

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 74.8 (#83)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Instruction Following | — | 1420 |

## Long Context

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 45.5 (#34)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| CL-bench | — | 22.2% |
| CL-bench Life | — | 11.9% |
| LMArena Longer Query | — | 1437 |

## Writing & Preference

- Devstral Small 2505: —
- Grok 4.20 (Non-Reasoning): 65.7 (#44)

| Benchmark | Devstral Small 2505 | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Text | — | 1451 |
| LMArena Creative Writing | — | 1438 |
| EQ-Bench Creative Writing | — | 1574 |
| LMArena Multi-Turn | — | 1456 |

## FAQ

### Is Devstral Small 2505 better than Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 34.3 on the Noometry Index. Devstral Small 2505 costs 10× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

### Which is cheaper, Devstral Small 2505 or Grok 4.20 (Non-Reasoning)?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Grok 4.20 (Non-Reasoning) lists at $1.25 and $2.50.

### Is Devstral Small 2505 or Grok 4.20 (Non-Reasoning) better for coding?

Grok 4.20 (Non-Reasoning) scores higher on coding benchmarks: 42.1 versus 38.9 in the Noometry coding category.

### Which has the bigger context window?

Grok 4.20 (Non-Reasoning) does, with 1M tokens against 128K.

### How many benchmarks do Devstral Small 2505 and Grok 4.20 (Non-Reasoning) share?

1 benchmark has published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.