# GPT-5.3 Codex vs GPT-5 Pro

> GPT-5.3 Codex and GPT-5 Pro score almost the same on the Noometry Index (45.8 vs 46.4), so choose on price, context window or the category you care about most.

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

## Summary

- They share 2 benchmarks with published results for both. GPT-5.3 Codex scores higher in 1 category and GPT-5 Pro in 0 categories; one gap is clear of the uncertainty.
- The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 44.0.
- The biggest single-benchmark swing is WeirdML: 79.3% for GPT-5.3 Codex and 60.4% for GPT-5 Pro.
- GPT-5.3 Codex is cheaper at $1.75 / $14 per million input/output tokens, against $15 / $120 for GPT-5 Pro.

## Snapshot

| | GPT-5.3 Codex | GPT-5 Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 45.8 | 46.4 |
| Rank | 69 | 64 |
| Context | 400K | 400K |
| Input $/M | $1.75 | $15 |
| Output $/M | $14 | $120 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- GPT-5 Pro: 44.0 (#80)

| Benchmark | GPT-5.3 Codex | GPT-5 Pro |
|---|---|---|
| WeirdML | 79.3% | 60.4% |
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| ALE-Bench | 1,655 | — |
| AlgoTune | — | 1.31 |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- GPT-5 Pro: —

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

## Reasoning

- GPT-5.3 Codex: —
- GPT-5 Pro: 38.9 (#62)

| Benchmark | GPT-5.3 Codex | GPT-5 Pro |
|---|---|---|
| Epoch Capabilities Index | 156.77 | 150.28 |
| ARC-AGI-2 | — | 18.3% |
| SimpleBench | — | 61.6% |
| Kagi LLM Benchmark | — | 76.8% |
| ARC-AGI-1 | — | 70.2% |
| EnigmaEval | — | 18.8% |

## Math

- GPT-5.3 Codex: —
- GPT-5 Pro: 48.5 (#63)

| Benchmark | GPT-5.3 Codex | GPT-5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 55.8% |
| FrontierMath Tier 4 | — | 19.5% |
| FrontierMath Tier 4 (v1) | — | 14.6% |

## Knowledge

- GPT-5.3 Codex: —
- GPT-5 Pro: 56.7 (#42)

| Benchmark | GPT-5.3 Codex | GPT-5 Pro |
|---|---|---|
| Humanity's Last Exam | — | 31.6% |

## FAQ

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

GPT-5.3 Codex and GPT-5 Pro score almost the same on the Noometry Index (45.8 vs 46.4), so choose on price, context window or the category you care about most.

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

GPT-5.3 Codex is cheaper. It lists at $1.75 per million input tokens and $14 per million output tokens; GPT-5 Pro lists at $15 and $120.

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

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 44.0 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 Pro share?

2 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and GPT-5 Pro has 12.