# Devstral Small 2505 vs GPT-5.3 Chat

> GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 34.3 on the Noometry Index. Devstral Small 2505 costs 32× less per token, which makes it the better buy when GPT-5.3 Chat's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/devstral-small-vs-gpt-5-3-chat
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where GPT-5.3 Chat leads 28.5 to 19.7.
- Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- Devstral Small 2505 has downloadable open weights; the other is API-only.

## Snapshot

| | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| Provider | Mistral AI | OpenAI |
| Noometry Index | 34.3 | 42.8 |
| Rank | 233 | 109 |
| Context | 128K | 128K |
| Input $/M | $0.10 | $1.75 |
| Output $/M | $0.30 | $14 |
| Weights | Open | Proprietary |

## Coding

- Devstral Small 2505: 38.9 (#166)
- GPT-5.3 Chat: 41.4 (#124)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| SWE-bench Verified (bash only) | 56.4% | — |
| SciCode | 28.8% | — |
| LMArena Coding | — | 1408 |

## Reasoning

- Devstral Small 2505: 19.7 (#252)
- GPT-5.3 Chat: 28.5 (#102)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| Kagi LLM Benchmark | 37.7% | — |
| CritPt | 0% | — |
| LMArena Hard Prompts | — | 1399 |

## Math

- Devstral Small 2505: —
- GPT-5.3 Chat: 38.2 (#142)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| LMArena Math | — | 1389 |

## Knowledge

- Devstral Small 2505: —
- GPT-5.3 Chat: 38.8 (#140)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| LMArena Expert | — | 1397 |

## Multilingual

- Devstral Small 2505: —
- GPT-5.3 Chat: 50.3 (#124)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| LMArena Non-English | — | 1382 |
| LMArena Chinese | — | 1432 |
| LMArena French | — | 1397 |
| LMArena German | — | 1384 |
| LMArena Japanese | — | 1352 |
| LMArena Korean | — | 1346 |
| LMArena Russian | — | 1400 |
| LMArena Spanish | — | 1371 |

## Instruction Following

- Devstral Small 2505: —
- GPT-5.3 Chat: 72.8 (#129)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| LMArena Instruction Following | — | 1378 |

## Long Context

- Devstral Small 2505: —
- GPT-5.3 Chat: 42.6 (#120)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| LMArena Longer Query | — | 1396 |

## Writing & Preference

- Devstral Small 2505: —
- GPT-5.3 Chat: 63.1 (#68)

| Benchmark | Devstral Small 2505 | GPT-5.3 Chat |
|---|---|---|
| LMArena Text | — | 1389 |
| LMArena Creative Writing | — | 1355 |
| EQ-Bench Creative Writing | — | 1690 |
| LMArena Multi-Turn | — | 1412 |

## FAQ

### Is Devstral Small 2505 better than GPT-5.3 Chat?

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 34.3 on the Noometry Index. Devstral Small 2505 costs 32× less per token, which makes it the better buy when GPT-5.3 Chat's lead doesn't matter for your workload.

### Which is cheaper, Devstral Small 2505 or GPT-5.3 Chat?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

### Is Devstral Small 2505 or GPT-5.3 Chat better for coding?

GPT-5.3 Chat scores higher on coding benchmarks: 41.4 versus 38.9 in the Noometry coding category.

### Which has the bigger context window?

Both accept 128K tokens.

### How many benchmarks do Devstral Small 2505 and GPT-5.3 Chat share?

0 benchmarks have published results for both models. Devstral Small 2505 has 4 scored results on Noometry and GPT-5.3 Chat has 18.