# GPT-4 Turbo vs GPT-5.1-Codex

> GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 30.5 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-4-turbo-vs-gpt-5-1-codex
- Last updated: 2026-10-12
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-4 Turbo scores higher in 0 categories and GPT-5.1-Codex in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5.1-Codex leads 30.3 to 9.0.
- GPT-5.1-Codex is cheaper at $1.25 / $10 per million input/output tokens, against $10 / $30 for GPT-4 Turbo.
- GPT-5.1-Codex accepts more context: 400K tokens versus 128K.

## Snapshot

| | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 30.5 | 38.6 |
| Rank | 292 | 186 |
| Context | 128K | 400K |
| Input $/M | $10 | $1.25 |
| Output $/M | $30 | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-4 Turbo: 33.8 (#249)
- GPT-5.1-Codex: 41.9 (#116)

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| SWE-bench Verified (bash only) | — | 66% |
| LMArena WebDev | — | 1337 |
| WeirdML | 18% | — |
| BigCodeBench Instruct | 48.2% | — |
| LMArena Coding | 1268 | — |
| BigCodeBench Complete | 58.2% | — |
| ALE-Bench | — | 1,245 |
| HumanEval+ | 86.6% | — |
| MBPP+ | 73.3% | — |

## Agentic & Tool Use

- GPT-4 Turbo: —
- GPT-5.1-Codex: 38.0 (#33)

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| METR Time Horizons | 36.7% | 70.8% |
| Terminal-Bench | — | 60.4% |

## Reasoning

- GPT-4 Turbo: 15.3 (#317)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| SimpleBench | 25.1% | — |
| Chess Puzzles | 6% | — |
| LMArena Hard Prompts | 1251 | — |
| DTBench | 61.6% | — |
| LMCA | 9.8% | — |
| Epoch Capabilities Index | 127.25 | — |
| ForecastBench | 59.4 | — |

## Math

- GPT-4 Turbo: 9.0 (#322)
- GPT-5.1-Codex: 30.3 (#235)

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| FrontierMath (Tiers 1-3) | 0.7% | — |
| OTIS Mock AIME 2024-2025 | 6.7% | — |
| ProofBench | — | 9% |
| LMArena Math | 1272 | — |
| MATH Level 5 | 46.7% | — |

## Knowledge

- GPT-4 Turbo: 24.3 (#268)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| GPQA Diamond | 46.6% | — |
| Confabulations | 28.4% | — |
| LMArena Expert | 1223 | — |
| MMLU | 81.3% | — |

## Multimodal

- GPT-4 Turbo: 30.6 (#110)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| LMArena Vision | 1090 | — |

## Multilingual

- GPT-4 Turbo: 40.5 (#216)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| LMArena Non-English | 1245 | — |
| LMArena Chinese | 1242 | — |
| LMArena French | 1276 | — |
| LMArena German | 1259 | — |
| LMArena Japanese | 1194 | — |
| LMArena Korean | 1187 | — |
| LMArena Russian | 1259 | — |
| LMArena Spanish | 1260 | — |

## Instruction Following

- GPT-4 Turbo: 65.8 (#216)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| LMArena Instruction Following | 1249 | — |

## Long Context

- GPT-4 Turbo: 38.0 (#206)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| LMArena Longer Query | 1254 | — |

## Writing & Preference

- GPT-4 Turbo: 47.7 (#206)
- GPT-5.1-Codex: —

| Benchmark | GPT-4 Turbo | GPT-5.1-Codex |
|---|---|---|
| LMArena Text | 1272 | — |
| LMArena Creative Writing | 1269 | — |
| LMArena Multi-Turn | 1267 | — |

## FAQ

### Is GPT-4 Turbo better than GPT-5.1-Codex?

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 30.5 on the Noometry Index.

### Which is cheaper, GPT-4 Turbo or GPT-5.1-Codex?

GPT-5.1-Codex is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-4 Turbo lists at $10 and $30.

### Is GPT-4 Turbo or GPT-5.1-Codex better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 33.8 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 128K.

### How many benchmarks do GPT-4 Turbo and GPT-5.1-Codex share?

1 benchmark has published results for both models. GPT-4 Turbo has 36 scored results on Noometry and GPT-5.1-Codex has 6.