# GPT-5.1-Codex vs GPT-5.4 Pro

> GPT-5.4 Pro is the stronger model overall, scoring 58.8 to 38.2 on the Noometry Index. GPT-5.1-Codex costs 20× less per token, which makes it the better buy when GPT-5.4 Pro's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-gpt-5-4-pro
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- The widest gap is in math, where GPT-5.4 Pro leads 72.0 to 29.3.
- GPT-5.1-Codex is cheaper at $1.25 / $10 per million input/output tokens, against $30 / $180 for GPT-5.4 Pro.
- GPT-5.4 Pro accepts more context: 1.05M tokens versus 400K.

## Snapshot

| | GPT-5.1-Codex | GPT-5.4 Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 38.2 | 58.8 |
| Rank | 178 | 16 |
| Context | 400K | 1.05M |
| Input $/M | $1.25 | $30 |
| Output $/M | $10 | $180 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.1-Codex: 41.7 (#107)
- GPT-5.4 Pro: 42.6 (#89)

| Benchmark | GPT-5.1-Codex | GPT-5.4 Pro |
|---|---|---|
| SWE-bench Verified (bash only) | 66% | — |
| LMArena WebDev | 1337 | — |
| WeirdML | — | 57.4% |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 37.8 (#32)
- GPT-5.4 Pro: —

| Benchmark | GPT-5.1-Codex | GPT-5.4 Pro |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- GPT-5.4 Pro: 71.0 (#10)

| Benchmark | GPT-5.1-Codex | GPT-5.4 Pro |
|---|---|---|
| ARC-AGI-2 | — | 83.3% |
| SimpleBench | — | 74.1% |
| ARC-AGI-1 | — | 94.5% |
| CritPt | — | 30% |
| Chess Puzzles | — | 58.6% |
| EnigmaEval | — | 23.8% |
| Epoch Capabilities Index | — | 159.12 |

## Math

- GPT-5.1-Codex: 29.3 (#218)
- GPT-5.4 Pro: 72.0 (#17)

| Benchmark | GPT-5.1-Codex | GPT-5.4 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 82.5% |
| FrontierMath Tier 4 | — | 58.5% |
| ProofBench | 9% | — |
| FrontierMath (Feb 2025 set) | — | 50% |
| FrontierMath Tier 4 (v1) | — | 37.5% |

## Knowledge

- GPT-5.1-Codex: —
- GPT-5.4 Pro: 68.3 (#6)

| Benchmark | GPT-5.1-Codex | GPT-5.4 Pro |
|---|---|---|
| GPQA Diamond | — | 94.6% |
| Humanity's Last Exam | — | 44.3% |
| SimpleQA Verified | — | 46.3% |
| Vectara Hallucination Rate | — | 8.3% |

## FAQ

### Is GPT-5.1-Codex better than GPT-5.4 Pro?

GPT-5.4 Pro is the stronger model overall, scoring 58.8 to 38.2 on the Noometry Index. GPT-5.1-Codex costs 20× less per token, which makes it the better buy when GPT-5.4 Pro's lead doesn't matter for your workload.

### Which is cheaper, GPT-5.1-Codex or GPT-5.4 Pro?

GPT-5.1-Codex is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-5.4 Pro lists at $30 and $180.

### Is GPT-5.1-Codex or GPT-5.4 Pro better for coding?

They score almost the same on coding (41.7 vs 42.6); test both on your own repository before choosing.

### Which has the bigger context window?

GPT-5.4 Pro does, with 1.05M tokens against 400K.

### How many benchmarks do GPT-5.1-Codex and GPT-5.4 Pro share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and GPT-5.4 Pro has 16.