# GPT-5.3 Chat vs Grok-3 mini

> GPT-5.3 Chat is the stronger model overall, scoring 42.1 to 41.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-chat-vs-grok-3-mini
- 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 5 categories and Grok-3 mini in 3 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.3 Chat leads 27.3 to 13.8.

## Snapshot

| | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 42.1 | 41.0 |
| Rank | 109 | 130 |
| Context | 128K | — |
| Input $/M | $1.75 | — |
| Output $/M | $14 | — |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Chat: 40.8 (#124)
- Grok-3 mini: 40.4 (#126)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Coding | 1408 | 1380 |
| Aider Polyglot | — | 49.3% |
| WeirdML | — | 42.6% |

## Reasoning

- GPT-5.3 Chat: 27.3 (#105)
- Grok-3 mini: 13.8 (#323)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1374 |
| ARC-AGI-2 | — | 0.4% |
| Kagi LLM Benchmark | — | 61.3% |
| ARC-AGI-1 | — | 16.5% |
| Epoch Capabilities Index | — | 140.35 |

## Math

- GPT-5.3 Chat: 35.4 (#146)
- Grok-3 mini: 40.3 (#78)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Math | 1389 | 1386 |
| OTIS Mock AIME 2024-2025 | — | 77.8% |
| Omni-MATH | — | 31.8% |
| MATH Level 5 | — | 90.9% |
| FrontierMath (Feb 2025 set) | — | 5.9% |

## Knowledge

- GPT-5.3 Chat: 38.2 (#137)
- Grok-3 mini: 46.3 (#75)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Expert | 1397 | 1395 |
| GPQA Diamond | — | 76.3% |
| MMLU-Pro | — | 79.9% |
| Confabulations | — | 10.8% |
| GPQA (HELM) | — | 67.5% |

## Multilingual

- GPT-5.3 Chat: 50.5 (#119)
- Grok-3 mini: 48.3 (#141)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Non-English | 1383 | 1352 |
| LMArena Chinese | 1433 | 1387 |
| LMArena French | 1398 | 1357 |
| LMArena German | 1384 | 1350 |
| LMArena Japanese | 1351 | 1343 |
| LMArena Korean | 1347 | 1336 |
| LMArena Russian | 1400 | 1352 |
| LMArena Spanish | 1371 | 1379 |

## Instruction Following

- GPT-5.3 Chat: 73.0 (#124)
- Grok-3 mini: 78.7 (#8)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Instruction Following | 1378 | 1356 |
| IFEval | — | 95.1% |

## Long Context

- GPT-5.3 Chat: 42.6 (#115)
- Grok-3 mini: 41.0 (#142)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Longer Query | 1396 | 1372 |
| Fiction.LiveBench | — | 66.7% |

## Writing & Preference

- GPT-5.3 Chat: 63.3 (#65)
- Grok-3 mini: 52.7 (#163)

| Benchmark | GPT-5.3 Chat | Grok-3 mini |
|---|---|---|
| LMArena Text | 1389 | 1370 |
| LMArena Creative Writing | 1356 | 1342 |
| LMArena Multi-Turn | 1413 | 1355 |
| Short-Story Creative Writing | — | 73.5% |
| EQ-Bench Creative Writing | 1690 | — |
| WildBench | — | 65.1% |

## FAQ

### Is GPT-5.3 Chat better than Grok-3 mini?

GPT-5.3 Chat is the stronger model overall, scoring 42.1 to 41.0 on the Noometry Index.

### Is GPT-5.3 Chat or Grok-3 mini better for coding?

They score almost the same on coding (40.8 vs 40.4); test both on your own repository before choosing.

### How many benchmarks do GPT-5.3 Chat and Grok-3 mini share?

17 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Grok-3 mini has 35.