# GPT-5.3 Codex vs Phi-4 Mini

> GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 30.4 on the Noometry Index. Phi-4 Mini costs 37× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-phi-4-mini
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where GPT-5.3 Codex leads 48.5 to 27.6.
- Phi-4 Mini is cheaper at $0.075 / $0.30 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- GPT-5.3 Codex accepts more context: 400K tokens versus 128K.
- Phi-4 Mini has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Codex | Phi-4 Mini |
|---|---|---|
| Provider | OpenAI | Microsoft |
| Noometry Index | 45.5 | 30.4 |
| Rank | 61 | 280 |
| Context | 400K | 128K |
| Input $/M | $1.75 | $0.075 |
| Output $/M | $14 | $0.30 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Codex: 48.5 (#51)
- Phi-4 Mini: 27.6 (#312)

| Benchmark | GPT-5.3 Codex | Phi-4 Mini |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1408 | — |
| SciCode | — | 10.8% |
| WeirdML | 79.3% | — |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 47.8 (#9)
- Phi-4 Mini: —

| Benchmark | GPT-5.3 Codex | Phi-4 Mini |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- Phi-4 Mini: 21.7 (#190)

| Benchmark | GPT-5.3 Codex | Phi-4 Mini |
|---|---|---|
| CritPt | — | 0% |
| Epoch Capabilities Index | 156.84 | — |

## Knowledge

- GPT-5.3 Codex: —
- Phi-4 Mini: 24.8 (#261)

| Benchmark | GPT-5.3 Codex | Phi-4 Mini |
|---|---|---|
| Vectara Hallucination Rate | — | 23.5% |

## FAQ

### Is GPT-5.3 Codex better than Phi-4 Mini?

GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 30.4 on the Noometry Index. Phi-4 Mini costs 37× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

### Which is cheaper, GPT-5.3 Codex or Phi-4 Mini?

Phi-4 Mini is cheaper. It lists at $0.075 per million input tokens and $0.30 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is GPT-5.3 Codex or Phi-4 Mini better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.5 versus 27.6 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 128K.

### How many benchmarks do GPT-5.3 Codex and Phi-4 Mini share?

0 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Phi-4 Mini has 3.