# GPT-5.3 Codex vs Hy4 preview

> GPT-5.3 Codex and Hy4 preview score almost the same on the Noometry Index (45.8 vs 45.3), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-hy4-preview
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5.3 Codex scores higher in 0 categories and Hy4 preview in 1 category; one gap is clear of the uncertainty.
- Hy4 preview is cheaper at $0.75 / $2.25 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- Hy4 preview accepts more context: 1.05M tokens versus 400K.
- Hy4 preview has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Codex | Hy4 preview |
|---|---|---|
| Provider | OpenAI | Tencent |
| Noometry Index | 45.8 | 45.3 |
| Rank | 69 | 73 |
| Context | 400K | 1.05M |
| Input $/M | $1.75 | $0.75 |
| Output $/M | $14 | $2.25 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- Hy4 preview: 51.6 (#38)

| Benchmark | GPT-5.3 Codex | Hy4 preview |
|---|---|---|
| LMArena WebDev | 1409 | 1632 |
| SWE-bench Verified | 74.8% | — |
| WeirdML | 79.3% | — |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- Hy4 preview: —

| Benchmark | GPT-5.3 Codex | Hy4 preview |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- Hy4 preview: 31.9 (#79)

| Benchmark | GPT-5.3 Codex | Hy4 preview |
|---|---|---|
| NYT Connections (extended) | — | 68.2% |
| Epoch Capabilities Index | 156.77 | — |

## Math

- GPT-5.3 Codex: —
- Hy4 preview: 55.7 (#42)

| Benchmark | GPT-5.3 Codex | Hy4 preview |
|---|---|---|
| ProofBench | — | 75% |

## FAQ

### Is GPT-5.3 Codex better than Hy4 preview?

GPT-5.3 Codex and Hy4 preview score almost the same on the Noometry Index (45.8 vs 45.3), so choose on price, context window or the category you care about most.

### Which is cheaper, GPT-5.3 Codex or Hy4 preview?

Hy4 preview is cheaper. It lists at $0.75 per million input tokens and $2.25 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is GPT-5.3 Codex or Hy4 preview better for coding?

Hy4 preview scores higher on coding benchmarks: 51.6 versus 48.6 in the Noometry coding category.

### Which has the bigger context window?

Hy4 preview does, with 1.05M tokens against 400K.

### How many benchmarks do GPT-5.3 Codex and Hy4 preview share?

1 benchmark has published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Hy4 preview has 3.