# Devstral Small 2505 vs Mercury

> Mercury is the stronger model overall, scoring 37.3 to 33.9 on the Noometry Index.

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

## Summary

- They share 1 benchmark with published results for both. Devstral Small 2505 scores higher in 2 categories and Mercury in 0 categories; one gap is clear of the uncertainty.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 37.7% for Devstral Small 2505 and 21.6% for Mercury.
- Devstral Small 2505 has downloadable open weights; the other is API-only.

## Snapshot

| | Devstral Small 2505 | Mercury |
|---|---|---|
| Provider | Mistral AI | Inception |
| Noometry Index | 33.9 | 37.3 |
| Rank | 228 | 192 |
| Context | 128K | — |
| Input $/M | $0.10 | — |
| Output $/M | $0.30 | — |
| Weights | Open | Proprietary |

## Coding

- Devstral Small 2505: 38.6 (#160)
- Mercury: 38.1 (#164)

| Benchmark | Devstral Small 2505 | Mercury |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| SciCode | 28.8% | — |
| LMArena Coding | — | 1323 |

## Reasoning

- Devstral Small 2505: 19.1 (#243)
- Mercury: 16.8 (#288)

| Benchmark | Devstral Small 2505 | Mercury |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | 21.6% |
| CritPt | 0% | — |
| LMArena Hard Prompts | — | 1284 |

## Multilingual

- Devstral Small 2505: —
- Mercury: 41.7 (#201)

| Benchmark | Devstral Small 2505 | Mercury |
|---|---|---|
| LMArena Non-English | — | 1259 |

## Instruction Following

- Devstral Small 2505: —
- Mercury: 65.3 (#220)

| Benchmark | Devstral Small 2505 | Mercury |
|---|---|---|
| LMArena Instruction Following | — | 1238 |

## Long Context

- Devstral Small 2505: —
- Mercury: 38.3 (#193)

| Benchmark | Devstral Small 2505 | Mercury |
|---|---|---|
| LMArena Longer Query | — | 1264 |

## Writing & Preference

- Devstral Small 2505: —
- Mercury: 46.2 (#216)

| Benchmark | Devstral Small 2505 | Mercury |
|---|---|---|
| LMArena Text | — | 1282 |
| LMArena Creative Writing | — | 1186 |
| LMArena Multi-Turn | — | 1283 |

## FAQ

### Is Devstral Small 2505 better than Mercury?

Mercury is the stronger model overall, scoring 37.3 to 33.9 on the Noometry Index.

### Is Devstral Small 2505 or Mercury better for coding?

They score almost the same on coding (38.6 vs 38.1); test both on your own repository before choosing.

### How many benchmarks do Devstral Small 2505 and Mercury share?

1 benchmark has published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Mercury has 9.