# GPT-5.3 Codex vs GPT-5-Codex

> GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 37.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-gpt-5-codex
- Last updated: 2026-10-11
- Shared benchmarks: 2

## Summary

- They share 2 benchmarks with published results for both. GPT-5.3 Codex scores higher in 2 categories and GPT-5-Codex in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 48.0 to 31.0.
- The biggest single-benchmark swing is Terminal-Bench: 78.4% for GPT-5.3 Codex and 44.3% for GPT-5-Codex.
- GPT-5-Codex is cheaper at $1.25 / $10 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.

## Snapshot

| | GPT-5.3 Codex | GPT-5-Codex |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 45.8 | 37.9 |
| Rank | 69 | 192 |
| Context | 400K | 400K |
| Input $/M | $1.75 | $1.25 |
| Output $/M | $14 | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- GPT-5-Codex: 42.4 (#103)

| Benchmark | GPT-5.3 Codex | GPT-5-Codex |
|---|---|---|
| WeirdML | 79.3% | 54.5% |
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- GPT-5-Codex: 31.0 (#72)

| Benchmark | GPT-5.3 Codex | GPT-5-Codex |
|---|---|---|
| Terminal-Bench | 78.4% | 44.3% |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- GPT-5-Codex: 30.9 (#83)

| Benchmark | GPT-5.3 Codex | GPT-5-Codex |
|---|---|---|
| Kagi LLM Benchmark | — | 70.3% |
| Epoch Capabilities Index | 156.77 | — |

## FAQ

### Is GPT-5.3 Codex better than GPT-5-Codex?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 37.9 on the Noometry Index.

### Which is cheaper, GPT-5.3 Codex or GPT-5-Codex?

GPT-5-Codex is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is GPT-5.3 Codex or GPT-5-Codex better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 42.4 in the Noometry coding category.

### Which has the bigger context window?

Both accept 400K tokens.

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

2 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and GPT-5-Codex has 3.