# GPT-5.3 Chat vs GPT-5 Mini

> GPT-5.3 Chat and GPT-5 Mini score almost the same on the Noometry Index (42.1 vs 41.7), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gpt-5-3-chat-vs-gpt-5-mini
- Last updated: 2026-10-10
- Shared benchmarks: 18

## Summary

- They share 18 benchmarks with published results for both. GPT-5.3 Chat scores higher in 5 categories and GPT-5 Mini in 3 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5 Mini leads 46.3 to 35.4.
- GPT-5 Mini is cheaper at $0.25 / $2 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- GPT-5 Mini accepts more context: 400K tokens versus 128K.

## Snapshot

| | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 42.1 | 41.7 |
| Rank | 109 | 115 |
| Context | 128K | 400K |
| Input $/M | $1.75 | $0.25 |
| Output $/M | $14 | $2 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Chat: 40.8 (#124)
- GPT-5 Mini: 40.0 (#134)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Coding | 1408 | 1406 |
| SWE-bench Verified | — | 64.7% |
| SWE-bench Verified (bash only) | — | 59.8% |
| SWE-bench Multilingual | — | 39.7% |
| SciCode | — | 39.2% |
| WeirdML | — | 52.7% |
| ALE-Bench | — | 799.77 |
| AlgoTune | — | 1.38 |

## Agentic & Tool Use

- GPT-5.3 Chat: —
- GPT-5 Mini: 31.0 (#64)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| Terminal-Bench | — | 34.8% |
| Berkeley Function Calling Leaderboard | — | 55.5% |
| Vending-Bench 2 | — | -31.18 |

## Reasoning

- GPT-5.3 Chat: 27.3 (#105)
- GPT-5 Mini: 24.1 (#153)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1380 |
| ARC-AGI-2 | — | 4.4% |
| Kagi LLM Benchmark | — | 70.3% |
| ARC-AGI-1 | — | 54.3% |
| CritPt | — | 0% |
| Chess Puzzles | — | 30% |
| EnigmaEval | — | 8.2% |
| Mystery Game Puzzles | — | 10% |
| DTBench | — | 80.5% |
| LMCA | — | 34.2% |
| Epoch Capabilities Index | — | 145.51 |
| ForecastBench | — | 61 |

## Math

- GPT-5.3 Chat: 35.4 (#146)
- GPT-5 Mini: 46.3 (#59)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Math | 1389 | 1377 |
| FrontierMath (Tiers 1-3) | — | 46.7% |
| FrontierMath Tier 4 | — | 12.2% |
| OTIS Mock AIME 2024-2025 | — | 86.7% |
| ProofBench | — | 9% |
| Omni-MATH | — | 72.2% |
| MATH Level 5 | — | 97.8% |
| FrontierMath (Feb 2025 set) | — | 27.2% |
| FrontierMath Tier 4 (v1) | — | 6.3% |

## Knowledge

- GPT-5.3 Chat: 38.2 (#137)
- GPT-5 Mini: 45.5 (#80)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Expert | 1397 | 1377 |
| GPQA Diamond | — | 75% |
| Humanity's Last Exam | — | 19.4% |
| SimpleQA Verified | — | 21.6% |
| MMLU-Pro | — | 83.5% |
| Confabulations | — | 13.3% |
| Vectara Hallucination Rate | — | 12.9% |
| GPQA (HELM) | — | 75.6% |

## Multimodal

- GPT-5.3 Chat: —
- GPT-5 Mini: 35.0 (#80)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Vision | — | 1202 |
| VPCT | — | 40.2% |

## Multilingual

- GPT-5.3 Chat: 50.5 (#119)
- GPT-5 Mini: 49.1 (#131)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Non-English | 1383 | 1363 |
| LMArena Chinese | 1433 | 1387 |
| LMArena French | 1398 | 1385 |
| LMArena German | 1384 | 1366 |
| LMArena Japanese | 1351 | 1342 |
| LMArena Korean | 1347 | 1306 |
| LMArena Russian | 1400 | 1362 |
| LMArena Spanish | 1371 | 1355 |

## Instruction Following

- GPT-5.3 Chat: 73.0 (#124)
- GPT-5 Mini: 76.4 (#43)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Instruction Following | 1378 | 1357 |
| IFEval | — | 92.7% |

## Long Context

- GPT-5.3 Chat: 42.6 (#115)
- GPT-5 Mini: 41.9 (#127)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Longer Query | 1396 | 1355 |
| Fiction.LiveBench | — | 69.4% |

## Writing & Preference

- GPT-5.3 Chat: 63.3 (#65)
- GPT-5 Mini: 55.4 (#143)

| Benchmark | GPT-5.3 Chat | GPT-5 Mini |
|---|---|---|
| LMArena Text | 1389 | 1373 |
| LMArena Creative Writing | 1356 | 1325 |
| EQ-Bench Creative Writing | 1690 | 1313 |
| LMArena Multi-Turn | 1413 | 1363 |
| Short-Story Creative Writing | — | 83.1% |
| WildBench | — | 85.5% |

## FAQ

### Is GPT-5.3 Chat better than GPT-5 Mini?

GPT-5.3 Chat and GPT-5 Mini score almost the same on the Noometry Index (42.1 vs 41.7), so choose on price, context window or the category you care about most.

### Which is cheaper, GPT-5.3 Chat or GPT-5 Mini?

GPT-5 Mini is cheaper. It lists at $0.25 per million input tokens and $2 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

### Is GPT-5.3 Chat or GPT-5 Mini better for coding?

They score almost the same on coding (40.8 vs 40.0); test both on your own repository before choosing.

### Which has the bigger context window?

GPT-5 Mini does, with 400K tokens against 128K.

### How many benchmarks do GPT-5.3 Chat and GPT-5 Mini share?

18 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and GPT-5 Mini has 60.