# GPT-5.3 Chat vs Mistral Small 3

> GPT-5.3 Chat is the stronger model overall, scoring 42.1 to 30.9 on the Noometry Index. Mistral Small 3 costs 84× 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/gpt-5-3-chat-vs-mistral-small-3
- Last updated: 2026-10-10
- Shared benchmarks: 17

## Summary

- They share 17 benchmarks with published results for both. GPT-5.3 Chat scores higher in 8 categories and Mistral Small 3 in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where GPT-5.3 Chat leads 63.3 to 32.4.
- Mistral Small 3 is cheaper at $0.05 / $0.08 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- GPT-5.3 Chat accepts more context: 128K tokens versus 33K.
- Mistral Small 3 has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Noometry Index | 42.1 | 30.9 |
| Rank | 109 | 268 |
| Context | 128K | 33K |
| Input $/M | $1.75 | $0.05 |
| Output $/M | $14 | $0.08 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Chat: 40.8 (#124)
- Mistral Small 3: 36.0 (#203)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Coding | 1408 | 1246 |
| BigCodeBench Instruct | — | 45.3% |
| BigCodeBench Complete | — | 50.4% |

## Reasoning

- GPT-5.3 Chat: 27.3 (#105)
- Mistral Small 3: 18.2 (#269)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1233 |
| Chess Puzzles | — | 0% |
| Epoch Capabilities Index | — | 127.06 |

## Math

- GPT-5.3 Chat: 35.4 (#146)
- Mistral Small 3: 15.3 (#290)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Math | 1389 | 1240 |
| OTIS Mock AIME 2024-2025 | — | 6.7% |

## Knowledge

- GPT-5.3 Chat: 38.2 (#137)
- Mistral Small 3: 25.0 (#258)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Expert | 1397 | 1202 |
| GPQA Diamond | — | 47.3% |
| Confabulations | — | 25.2% |

## Multilingual

- GPT-5.3 Chat: 50.5 (#119)
- Mistral Small 3: 37.5 (#231)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Non-English | 1383 | 1198 |
| LMArena Chinese | 1433 | 1204 |
| LMArena French | 1398 | 1202 |
| LMArena German | 1384 | 1211 |
| LMArena Japanese | 1351 | 1111 |
| LMArena Korean | 1347 | 1188 |
| LMArena Russian | 1400 | 1216 |
| LMArena Spanish | 1371 | — |

## Instruction Following

- GPT-5.3 Chat: 73.0 (#124)
- Mistral Small 3: 63.9 (#224)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Instruction Following | 1378 | 1214 |

## Long Context

- GPT-5.3 Chat: 42.6 (#115)
- Mistral Small 3: 37.8 (#206)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Longer Query | 1396 | 1246 |

## Writing & Preference

- GPT-5.3 Chat: 63.3 (#65)
- Mistral Small 3: 32.4 (#275)

| Benchmark | GPT-5.3 Chat | Mistral Small 3 |
|---|---|---|
| LMArena Text | 1389 | 1234 |
| LMArena Creative Writing | 1356 | 1195 |
| EQ-Bench Creative Writing | 1690 | 707 |
| LMArena Multi-Turn | 1413 | 1217 |

## FAQ

### Is GPT-5.3 Chat better than Mistral Small 3?

GPT-5.3 Chat is the stronger model overall, scoring 42.1 to 30.9 on the Noometry Index. Mistral Small 3 costs 84× 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, GPT-5.3 Chat or Mistral Small 3?

Mistral Small 3 is cheaper. It lists at $0.05 per million input tokens and $0.08 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

### Is GPT-5.3 Chat or Mistral Small 3 better for coding?

GPT-5.3 Chat scores higher on coding benchmarks: 40.8 versus 36.0 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.3 Chat does, with 128K tokens against 33K.

### How many benchmarks do GPT-5.3 Chat and Mistral Small 3 share?

17 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Mistral Small 3 has 24.