# DeepSeek-V3.1 vs GPT-5.2 Codex

> DeepSeek-V3.1 and GPT-5.2 Codex score almost the same on the Noometry Index (42.8 vs 42.6), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/deepseek-v3-1-vs-gpt-5-2-codex
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where GPT-5.2 Codex leads 45.5 to 40.3.
- DeepSeek-V3.1 is cheaper at $0.25 / $0.95 per million input/output tokens, against $1.75 / $14 for GPT-5.2 Codex.
- GPT-5.2 Codex accepts more context: 400K tokens versus 164K.
- DeepSeek-V3.1 has downloadable open weights; the other is API-only.

## Snapshot

| | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Noometry Index | 42.8 | 42.6 |
| Rank | 108 | 111 |
| Context | 164K | 400K |
| Input $/M | $0.25 | $1.75 |
| Output $/M | $0.95 | $14 |
| Weights | Open | Proprietary |

## Coding

- DeepSeek-V3.1: 40.3 (#144)
- GPT-5.2 Codex: 45.5 (#71)

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| SWE-bench Verified (bash only) | — | 72.8% |
| LMArena WebDev | — | 1339 |
| SWE-bench Multilingual | — | 66.3% |
| WeirdML | 38.4% | — |
| LMArena Coding | 1417 | — |
| ALE-Bench | — | 1,300 |

## Agentic & Tool Use

- DeepSeek-V3.1: —
- GPT-5.2 Codex: 41.0 (#22)

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| Terminal-Bench | — | 66.5% |

## Reasoning

- DeepSeek-V3.1: 27.9 (#110)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| SimpleBench | 40% | — |
| Kagi LLM Benchmark | 53.2% | — |
| LMArena Hard Prompts | 1417 | — |
| DTBench | 82.7% | — |
| LMCA | 24.3% | — |
| Epoch Capabilities Index | 139.92 | — |
| ForecastBench | 58 | — |

## Math

- DeepSeek-V3.1: 38.9 (#122)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| LMArena Math | 1420 | — |

## Knowledge

- DeepSeek-V3.1: 43.7 (#90)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| Vectara Hallucination Rate | 5.5% | — |
| LMArena Expert | 1405 | — |

## Multilingual

- DeepSeek-V3.1: 51.6 (#106)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| LMArena Non-English | 1400 | — |
| LMArena Chinese | 1469 | — |
| LMArena French | 1447 | — |
| LMArena German | 1411 | — |
| LMArena Japanese | 1378 | — |
| LMArena Korean | 1337 | — |
| LMArena Russian | 1405 | — |
| LMArena Spanish | 1431 | — |

## Instruction Following

- DeepSeek-V3.1: 73.9 (#110)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| LMArena Instruction Following | 1400 | — |

## Long Context

- DeepSeek-V3.1: 36.3 (#232)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| Fiction.LiveBench | 52.8% | — |
| LMArena Longer Query | 1422 | — |

## Writing & Preference

- DeepSeek-V3.1: 60.3 (#98)
- GPT-5.2 Codex: —

| Benchmark | DeepSeek-V3.1 | GPT-5.2 Codex |
|---|---|---|
| LMArena Text | 1420 | — |
| LMArena Creative Writing | 1401 | — |
| EQ-Bench Creative Writing | 1436 | — |
| LMArena Multi-Turn | 1408 | — |

## FAQ

### Is DeepSeek-V3.1 better than GPT-5.2 Codex?

DeepSeek-V3.1 and GPT-5.2 Codex score almost the same on the Noometry Index (42.8 vs 42.6), so choose on price, context window or the category you care about most.

### Which is cheaper, DeepSeek-V3.1 or GPT-5.2 Codex?

DeepSeek-V3.1 is cheaper. It lists at $0.25 per million input tokens and $0.95 per million output tokens; GPT-5.2 Codex lists at $1.75 and $14.

### Is DeepSeek-V3.1 or GPT-5.2 Codex better for coding?

GPT-5.2 Codex scores higher on coding benchmarks: 45.5 versus 40.3 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.2 Codex does, with 400K tokens against 164K.

### How many benchmarks do DeepSeek-V3.1 and GPT-5.2 Codex share?

0 benchmarks have published results for both models. DeepSeek-V3.1 has 27 scored results on Noometry and GPT-5.2 Codex has 5.