# Devstral Small 2505 vs Llama 3.1-405B

> Devstral Small 2505 is the stronger model overall, scoring 34.3 to 30.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/devstral-small-vs-llama-3-1-405b
- Last updated: 2026-10-12
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. Devstral Small 2505 scores higher in 2 categories and Llama 3.1-405B in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in coding, where Devstral Small 2505 leads 38.9 to 33.1.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 37.7% for Devstral Small 2505 and 45% for Llama 3.1-405B.

## Snapshot

| | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| Provider | Mistral AI | Meta |
| Noometry Index | 34.3 | 30.7 |
| Rank | 233 | 288 |
| Context | 128K | — |
| Input $/M | $0.10 | — |
| Output $/M | $0.30 | — |
| Weights | Open | Open |

## Coding

- Devstral Small 2505: 38.9 (#166)
- Llama 3.1-405B: 33.1 (#262)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| SciCode | 28.8% | — |
| WeirdML | — | 21.4% |
| LMArena Coding | — | 1291 |

## Agentic & Tool Use

- Devstral Small 2505: —
- Llama 3.1-405B: 21.0 (#140)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| TheAgentCompany | — | 7.4% |
| Cybench | — | 7.5% |

## Reasoning

- Devstral Small 2505: 19.7 (#252)
- Llama 3.1-405B: 16.8 (#300)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | 45% |
| SimpleBench | — | 23% |
| CritPt | 0% | — |
| LMArena Hard Prompts | — | 1269 |
| DTBench | — | 61.4% |
| BIG-Bench Hard | — | 82.9% |
| Epoch Capabilities Index | — | 128.75 |
| ForecastBench | — | 59.9 |
| HellaSwag | — | 89.2% |
| PIQA | — | 85.9% |
| WinoGrande | — | 89.2% |

## Math

- Devstral Small 2505: —
- Llama 3.1-405B: 18.4 (#290)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 9.7% |
| Omni-MATH | — | 24.9% |
| LMArena Math | — | 1281 |
| MATH Level 5 | — | 49.8% |

## Knowledge

- Devstral Small 2505: —
- Llama 3.1-405B: 30.4 (#227)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| GPQA Diamond | — | 50.9% |
| MMLU-Pro | — | 72.3% |
| Confabulations | — | 17.6% |
| GPQA (HELM) | — | 52.2% |
| LMArena Expert | — | 1243 |
| ARC (AI2) Challenge | — | 95.3% |
| MMLU | — | 84.5% |
| TriviaQA | — | 82.7% |

## Multilingual

- Devstral Small 2505: —
- Llama 3.1-405B: 40.7 (#214)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| LMArena Non-English | — | 1248 |
| LMArena Chinese | — | 1242 |
| LMArena French | — | 1279 |
| LMArena German | — | 1252 |
| LMArena Japanese | — | 1208 |
| LMArena Korean | — | 1184 |
| LMArena Russian | — | 1265 |
| LMArena Spanish | — | 1260 |

## Instruction Following

- Devstral Small 2505: —
- Llama 3.1-405B: 65.9 (#214)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| IFEval | — | 81.1% |
| LMArena Instruction Following | — | 1259 |

## Long Context

- Devstral Small 2505: —
- Llama 3.1-405B: 38.4 (#197)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| LMArena Longer Query | — | 1266 |

## Writing & Preference

- Devstral Small 2505: —
- Llama 3.1-405B: 38.9 (#251)

| Benchmark | Devstral Small 2505 | Llama 3.1-405B |
|---|---|---|
| LMArena Text | — | 1284 |
| LMArena Creative Writing | — | 1262 |
| EQ-Bench Creative Writing | — | 870 |
| WildBench | — | 78.3% |
| LMArena Multi-Turn | — | 1297 |

## FAQ

### Is Devstral Small 2505 better than Llama 3.1-405B?

Devstral Small 2505 is the stronger model overall, scoring 34.3 to 30.7 on the Noometry Index.

### Is Devstral Small 2505 or Llama 3.1-405B better for coding?

Devstral Small 2505 scores higher on coding benchmarks: 38.9 versus 33.1 in the Noometry coding category.

### How many benchmarks do Devstral Small 2505 and Llama 3.1-405B share?

1 benchmark has published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Llama 3.1-405B has 42.