# Claude 2.1 vs GPT-5.1-Codex

> GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 25.2 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-gpt-5-1-codex
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in math, where GPT-5.1-Codex leads 30.3 to 10.2.

## Snapshot

| | Claude 2.1 | GPT-5.1-Codex |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 25.2 | 38.6 |
| Rank | 345 | 186 |
| Context | — | 400K |
| Input $/M | — | $1.25 |
| Output $/M | — | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2.1: 26.2 (#327)
- GPT-5.1-Codex: 41.9 (#116)

| Benchmark | Claude 2.1 | GPT-5.1-Codex |
|---|---|---|
| SWE-bench Verified (bash only) | — | 66% |
| LMArena WebDev | — | 1337 |
| WeirdML | 7.1% | — |
| ALE-Bench | — | 1,245 |

## Agentic & Tool Use

- Claude 2.1: —
- GPT-5.1-Codex: 38.0 (#33)

| Benchmark | Claude 2.1 | GPT-5.1-Codex |
|---|---|---|
| Terminal-Bench | — | 60.4% |
| METR Time Horizons | — | 70.8% |

## Reasoning

- Claude 2.1: 21.4 (#221)
- GPT-5.1-Codex: —

| Benchmark | Claude 2.1 | GPT-5.1-Codex |
|---|---|---|
| DTBench | 51% | — |
| Epoch Capabilities Index | 119.27 | — |
| ForecastBench | 54.2 | — |

## Math

- Claude 2.1: 10.2 (#315)
- GPT-5.1-Codex: 30.3 (#235)

| Benchmark | Claude 2.1 | GPT-5.1-Codex |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | — |
| ProofBench | — | 9% |

## Knowledge

- Claude 2.1: 15.4 (#292)
- GPT-5.1-Codex: —

| Benchmark | Claude 2.1 | GPT-5.1-Codex |
|---|---|---|
| GPQA Diamond | 33% | — |
| MMLU | 73.5% | — |

## FAQ

### Is Claude 2.1 better than GPT-5.1-Codex?

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 25.2 on the Noometry Index.

### Is Claude 2.1 or GPT-5.1-Codex better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 26.2 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and GPT-5.1-Codex share?

0 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and GPT-5.1-Codex has 6.