# GLM-4.5-Air vs GPT-5.2 Codex

> GPT-5.2 Codex is the stronger model overall, scoring 42.2 to 38.7 on the Noometry Index. GLM-4.5-Air costs 11× less per token, which makes it the better buy when GPT-5.2 Codex's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/glm-4-5-air-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 45.4 to 34.5.
- GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $1.75 / $14 for GPT-5.2 Codex.
- GPT-5.2 Codex accepts more context: 400K tokens versus 131K.
- GLM-4.5-Air has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 38.7 | 42.2 |
| Rank | 169 | 107 |
| Context | 131K | 400K |
| Input $/M | $0.20 | $1.75 |
| Output $/M | $1.10 | $14 |
| Weights | Open | Proprietary |

## Coding

- GLM-4.5-Air: 34.5 (#225)
- GPT-5.2 Codex: 45.4 (#66)

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| SWE-bench Verified (bash only) | — | 72.8% |
| LMArena WebDev | — | 1339 |
| SWE-bench Multilingual | — | 66.3% |
| GSO | 2.9% | — |
| LMArena Coding | 1397 | — |
| ALE-Bench | — | 1,300 |

## Agentic & Tool Use

- GLM-4.5-Air: —
- GPT-5.2 Codex: 40.7 (#20)

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| Terminal-Bench | — | 66.5% |

## Reasoning

- GLM-4.5-Air: 23.3 (#166)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| Kagi LLM Benchmark | 43% | — |
| LMArena Hard Prompts | 1379 | — |
| ForecastBench | 59.2 | — |

## Math

- GLM-4.5-Air: 33.8 (#166)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| Omni-MATH | 39.1% | — |
| LMArena Math | 1396 | — |

## Knowledge

- GLM-4.5-Air: 34.6 (#184)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| Humanity's Last Exam | 8.1% | — |
| MMLU-Pro | 76.2% | — |
| Vectara Hallucination Rate | 9.3% | — |
| GPQA (HELM) | 59.4% | — |
| LMArena Expert | 1370 | — |

## Multilingual

- GLM-4.5-Air: 49.4 (#130)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| LMArena Non-English | 1366 | — |
| LMArena Chinese | 1427 | — |
| LMArena French | 1399 | — |
| LMArena German | 1376 | — |
| LMArena Japanese | 1348 | — |
| LMArena Korean | 1306 | — |
| LMArena Russian | 1373 | — |
| LMArena Spanish | 1385 | — |

## Instruction Following

- GLM-4.5-Air: 69.8 (#165)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| IFEval | 81.2% | — |
| LMArena Instruction Following | 1353 | — |

## Long Context

- GLM-4.5-Air: 41.6 (#130)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| LMArena Longer Query | 1367 | — |

## Writing & Preference

- GLM-4.5-Air: 56.1 (#134)
- GPT-5.2 Codex: —

| Benchmark | GLM-4.5-Air | GPT-5.2 Codex |
|---|---|---|
| LMArena Text | 1384 | — |
| LMArena Creative Writing | 1343 | — |
| WildBench | 78.9% | — |
| LMArena Multi-Turn | 1371 | — |

## FAQ

### Is GLM-4.5-Air better than GPT-5.2 Codex?

GPT-5.2 Codex is the stronger model overall, scoring 42.2 to 38.7 on the Noometry Index. GLM-4.5-Air costs 11× less per token, which makes it the better buy when GPT-5.2 Codex's lead doesn't matter for your workload.

### Which is cheaper, GLM-4.5-Air or GPT-5.2 Codex?

GLM-4.5-Air is cheaper. It lists at $0.20 per million input tokens and $1.10 per million output tokens; GPT-5.2 Codex lists at $1.75 and $14.

### Is GLM-4.5-Air or GPT-5.2 Codex better for coding?

GPT-5.2 Codex scores higher on coding benchmarks: 45.4 versus 34.5 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.2 Codex does, with 400K tokens against 131K.

### How many benchmarks do GLM-4.5-Air and GPT-5.2 Codex share?

0 benchmarks have published results for both models. GLM-4.5-Air has 27 scored results on Noometry and GPT-5.2 Codex has 5.