# GPT-5.3 Chat vs Phi 3 Mini 128k Instruct

> GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 29.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-chat-vs-phi-3-mini-128k-instruct
- 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 Phi 3 Mini 128k Instruct in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where GPT-5.3 Chat leads 63.1 to 27.1.
- Phi 3 Mini 128k Instruct has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| Provider | OpenAI | Microsoft |
| Noometry Index | 42.8 | 29.7 |
| Rank | 109 | 305 |
| Context | 128K | — |
| Input $/M | $1.75 | — |
| Output $/M | $14 | — |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Chat: 41.4 (#124)
- Phi 3 Mini 128k Instruct: 28.8 (#312)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Coding | 1408 | 1039 |
| BigCodeBench Instruct | — | 29.6% |
| BigCodeBench Complete | — | 40.6% |

## Reasoning

- GPT-5.3 Chat: 28.5 (#102)
- Phi 3 Mini 128k Instruct: 19.6 (#256)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1028 |

## Math

- GPT-5.3 Chat: 38.2 (#142)
- Phi 3 Mini 128k Instruct: 31.6 (#222)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Math | 1389 | 1089 |

## Knowledge

- GPT-5.3 Chat: 38.8 (#140)
- Phi 3 Mini 128k Instruct: 26.8 (#254)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Expert | 1397 | 984 |

## Multilingual

- GPT-5.3 Chat: 50.3 (#124)
- Phi 3 Mini 128k Instruct: 25.2 (#285)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Non-English | 1382 | 1000 |
| LMArena Chinese | 1432 | 1016 |
| LMArena French | 1397 | 1039 |
| LMArena German | 1384 | 1006 |
| LMArena Japanese | 1352 | 899 |
| LMArena Korean | 1346 | 856 |
| LMArena Russian | 1400 | 1004 |
| LMArena Spanish | 1371 | 1059 |

## Instruction Following

- GPT-5.3 Chat: 72.8 (#129)
- Phi 3 Mini 128k Instruct: 51.8 (#294)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Instruction Following | 1378 | 1023 |

## Long Context

- GPT-5.3 Chat: 42.6 (#120)
- Phi 3 Mini 128k Instruct: 30.4 (#289)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Longer Query | 1396 | 996 |

## Writing & Preference

- GPT-5.3 Chat: 63.1 (#68)
- Phi 3 Mini 128k Instruct: 27.1 (#301)

| Benchmark | GPT-5.3 Chat | Phi 3 Mini 128k Instruct |
|---|---|---|
| LMArena Text | 1389 | 1050 |
| LMArena Creative Writing | 1355 | 1024 |
| LMArena Multi-Turn | 1412 | 989 |
| EQ-Bench Creative Writing | 1690 | — |

## FAQ

### Is GPT-5.3 Chat better than Phi 3 Mini 128k Instruct?

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 29.7 on the Noometry Index.

### Is GPT-5.3 Chat or Phi 3 Mini 128k Instruct better for coding?

GPT-5.3 Chat scores higher on coding benchmarks: 41.4 versus 28.8 in the Noometry coding category.

### How many benchmarks do GPT-5.3 Chat and Phi 3 Mini 128k Instruct share?

17 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Phi 3 Mini 128k Instruct has 19.