# DeepSeek-V3.1-Terminus vs Devstral Small 2505

> DeepSeek-V3.1-Terminus is the stronger model overall, scoring 42.6 to 33.9 on the Noometry Index. Devstral Small 2505 costs 3.2× less per token, which makes it the better buy when DeepSeek-V3.1-Terminus's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/deepseek-v3-1-terminus-vs-devstral-small
- Last updated: 2026-10-10
- Shared benchmarks: 3

## Summary

- They share 3 benchmarks with published results for both. DeepSeek-V3.1-Terminus scores higher in 2 categories and Devstral Small 2505 in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where DeepSeek-V3.1-Terminus leads 25.7 to 19.1.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 57.4% for DeepSeek-V3.1-Terminus and 37.7% for Devstral Small 2505.
- Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $0.30 / $1 for DeepSeek-V3.1-Terminus.
- DeepSeek-V3.1-Terminus accepts more context: 164K tokens versus 128K.

## Snapshot

| | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| Provider | DeepSeek | Mistral AI |
| Noometry Index | 42.6 | 33.9 |
| Rank | 96 | 228 |
| Context | 164K | 128K |
| Input $/M | $0.30 | $0.10 |
| Output $/M | $1 | $0.30 |
| Weights | Open | Open |

## Coding

- DeepSeek-V3.1-Terminus: 41.5 (#114)
- Devstral Small 2505: 38.6 (#160)

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| SciCode | 40.6% | 28.8% |
| SWE-bench Verified (bash only) | — | 56.4% |
| LMArena Coding | 1426 | — |
| ALE-Bench | 745.17 | — |

## Reasoning

- DeepSeek-V3.1-Terminus: 25.7 (#126)
- Devstral Small 2505: 19.1 (#243)

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| Kagi LLM Benchmark | 57.4% | 37.7% |
| CritPt | 1.7% | 0% |
| LMArena Hard Prompts | 1427 | — |
| DTBench | 81.3% | — |
| LMCA | 28.6% | — |

## Math

- DeepSeek-V3.1-Terminus: 35.7 (#138)
- Devstral Small 2505: —

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| LMArena Math | 1402 | — |

## Multilingual

- DeepSeek-V3.1-Terminus: 52.3 (#87)
- Devstral Small 2505: —

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| LMArena Non-English | 1407 | — |
| LMArena Russian | 1434 | — |

## Instruction Following

- DeepSeek-V3.1-Terminus: 74.4 (#96)
- Devstral Small 2505: —

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| LMArena Instruction Following | 1406 | — |

## Long Context

- DeepSeek-V3.1-Terminus: 43.5 (#88)
- Devstral Small 2505: —

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| LMArena Longer Query | 1426 | — |

## Writing & Preference

- DeepSeek-V3.1-Terminus: 61.3 (#87)
- Devstral Small 2505: —

| Benchmark | DeepSeek-V3.1-Terminus | Devstral Small 2505 |
|---|---|---|
| LMArena Text | 1420 | — |
| LMArena Creative Writing | 1404 | — |
| LMArena Multi-Turn | 1411 | — |

## FAQ

### Is DeepSeek-V3.1-Terminus better than Devstral Small 2505?

DeepSeek-V3.1-Terminus is the stronger model overall, scoring 42.6 to 33.9 on the Noometry Index. Devstral Small 2505 costs 3.2× less per token, which makes it the better buy when DeepSeek-V3.1-Terminus's lead doesn't matter for your workload.

### Which is cheaper, DeepSeek-V3.1-Terminus or Devstral Small 2505?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; DeepSeek-V3.1-Terminus lists at $0.30 and $1.

### Is DeepSeek-V3.1-Terminus or Devstral Small 2505 better for coding?

DeepSeek-V3.1-Terminus scores higher on coding benchmarks: 41.5 versus 38.6 in the Noometry coding category.

### Which has the bigger context window?

DeepSeek-V3.1-Terminus does, with 164K tokens against 128K.

### How many benchmarks do DeepSeek-V3.1-Terminus and Devstral Small 2505 share?

3 benchmarks have published results for both models. DeepSeek-V3.1-Terminus has 16 scored results on Noometry and Devstral Small 2505 has 4.