# GPT-5.3 Chat vs Phi 3 Medium 4k Instruct

> GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 33.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-chat-vs-phi-3-medium-4k-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 Medium 4k 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 34.1.
- Phi 3 Medium 4k Instruct has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| Provider | OpenAI | Microsoft |
| Noometry Index | 42.8 | 33.0 |
| Rank | 109 | 250 |
| Context | 128K | — |
| Input $/M | $1.75 | — |
| Output $/M | $14 | — |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Chat: 41.4 (#124)
- Phi 3 Medium 4k Instruct: 32.9 (#268)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Coding | 1408 | 1130 |

## Reasoning

- GPT-5.3 Chat: 28.5 (#102)
- Phi 3 Medium 4k Instruct: 21.7 (#214)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1127 |

## Math

- GPT-5.3 Chat: 38.2 (#142)
- Phi 3 Medium 4k Instruct: 33.4 (#202)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Math | 1389 | 1173 |

## Knowledge

- GPT-5.3 Chat: 38.8 (#140)
- Phi 3 Medium 4k Instruct: 30.2 (#229)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Expert | 1397 | 1108 |

## Multilingual

- GPT-5.3 Chat: 50.3 (#124)
- Phi 3 Medium 4k Instruct: 30.6 (#263)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Non-English | 1382 | 1094 |
| LMArena Chinese | 1432 | 1108 |
| LMArena French | 1397 | 1110 |
| LMArena German | 1384 | 1101 |
| LMArena Japanese | 1352 | 1042 |
| LMArena Korean | 1346 | 954 |
| LMArena Russian | 1400 | 1145 |
| LMArena Spanish | 1371 | 1095 |

## Instruction Following

- GPT-5.3 Chat: 72.8 (#129)
- Phi 3 Medium 4k Instruct: 57.6 (#268)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Instruction Following | 1378 | 1113 |

## Long Context

- GPT-5.3 Chat: 42.6 (#120)
- Phi 3 Medium 4k Instruct: 34.0 (#255)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Longer Query | 1396 | 1120 |

## Writing & Preference

- GPT-5.3 Chat: 63.1 (#68)
- Phi 3 Medium 4k Instruct: 34.1 (#272)

| Benchmark | GPT-5.3 Chat | Phi 3 Medium 4k Instruct |
|---|---|---|
| LMArena Text | 1389 | 1138 |
| LMArena Creative Writing | 1355 | 1107 |
| LMArena Multi-Turn | 1412 | 1088 |
| EQ-Bench Creative Writing | 1690 | — |

## FAQ

### Is GPT-5.3 Chat better than Phi 3 Medium 4k Instruct?

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 33.0 on the Noometry Index.

### Is GPT-5.3 Chat or Phi 3 Medium 4k Instruct better for coding?

GPT-5.3 Chat scores higher on coding benchmarks: 41.4 versus 32.9 in the Noometry coding category.

### How many benchmarks do GPT-5.3 Chat and Phi 3 Medium 4k Instruct share?

17 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Phi 3 Medium 4k Instruct has 17.