# GLM-5.3-Flash vs GPT-5.2-Codex

> Side-by-side benchmark comparison for GLM-5.3-Flash and GPT-5.2-Codex across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/glm-5-3-flash-vs-gpt-5-2-codex
- Last updated: October 10, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: GLM-5.3-Flash and GPT-5.2-Codex share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- GLM-5.3-Flash has the lower published output-token price.
- GLM-5.3-Flash has the larger published context window at 1M.

## Model Snapshot

| Property | GLM-5.3-Flash | GPT-5.2-Codex |
|----------|----------|----------|
| Creator | Z.AI | OpenAI |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 400K |
| Independent public score (not head-to-head) | 57.36 | 55.43 |
| Benchmarks Covered | 21 | 5 |
| Pricing (input/output) | $0.00 / $0.00 | $1.75 / $14.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GLM-5.3-Flash public-lane score: 55.7 (Supported · #34/123)
- GPT-5.2-Codex public-lane score: 40.4 (Estimated · #60/123)

| Benchmark | GLM-5.3-Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 84.3% | Coming soon | Coming soon |
| Toolathlon-Verified | 78.4% | Coming soon | Coming soon |
| AutomationBench | 48.8% | Coming soon | Coming soon |
| Agents' Last Exam | 26.3% | Coming soon | Coming soon |
| HLE w/ tools | 55.3% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 62.9% | Coming soon | Coming soon |
| Gert Labs | Coming soon | 51.79% | Coming soon |
| JobBench | Coming soon | 26.0% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GLM-5.3-Flash public-lane score: 49.3 (Supported · #42/146)
- GPT-5.2-Codex public-lane score: 45.2 (Supported · #51/146)

| Benchmark | GLM-5.3-Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 84.3% | Coming soon | Coming soon |
| DeepSWE | 63.4% | Coming soon | Coming soon |
| NL2Repo | 56.3% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 80.5% | 88.0% | GPT-5.2-Codex |
| SWE-bench (Vals) | 92.0% | 72.4% | GLM-5.3-Flash |
| OpenHarmony Bench | 57.3% | Coming soon | Coming soon |
| FrontierSWE v2 | 18.1% | Coming soon | Coming soon |
| Bug Hunt Bench | 17.7 fixes | Coming soon | Coming soon |
| Vibe Code Bench | Coming soon | 37.91% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GLM-5.3-Flash public-lane score: 81.1 (#11/28)
- GPT-5.2-Codex public-lane score: 82.7 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GLM-5.3-Flash public-lane score: 84 (#14/54)
- GPT-5.2-Codex public-lane score: 76.9 (Unranked · 1 rankable row)

| Benchmark | GLM-5.3-Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| OfficeQA Pro | 62.4% | Coming soon | Coming soon |
| CharXiv | 89.4% | Coming soon | Coming soon |
| Chartography (tools) | 78.0% | Coming soon | Coming soon |
| BabyVision | 53.4% | Coming soon | Coming soon |
| MMVU | 80.5% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- GLM-5.3-Flash public-lane score: 60.5 (Supported · #43/177)
- GPT-5.2-Codex public-lane score: 56.8 (Estimated · #50/177)

| Benchmark | GLM-5.3-Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 86.4% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 86.1% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GLM-5.3-Flash public-lane score: Coming soon
- GPT-5.2-Codex public-lane score: 93.8 (#4/127)

## FAQ

### Is there enough evidence to pick between GLM-5.3-Flash and GPT-5.2-Codex?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GLM-5.3-Flash vs GLM-5.3](/compare/glm-5-3-vs-glm-5-3-flash)
- [GPT-5.2-Codex vs GLM-5.3](/compare/glm-5-3-vs-gpt-5-2-codex)
- [GLM-5.3-Flash vs GLM-5.2](/compare/glm-5-2-vs-glm-5-3-flash)
- [GPT-5.2-Codex vs GLM-5.2](/compare/glm-5-2-vs-gpt-5-2-codex)

## Explore More

- [GLM-5.3-Flash profile](/models/glm-5-3-flash)
- [GPT-5.2-Codex profile](/models/gpt-5-2-codex)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)