GLM-5.3 vs GPT-5.2-Codex
GLM-5.3 
GPT-5.2-Codex Verdict
- GLM-5.3 and GPT-5.2-Codex are level on quality (61.4 vs 60.8).
- GLM-5.3 is stronger in agents & tools, composite, knowledge.
- GPT-5.2-Codex is stronger in long context, coding, instruction following, multimodal.
- GLM-5.3 is 2.2× cheaper ($2.15 vs $4.81 per 1M blended).
- GLM-5.3 streams 2.2× faster (67 vs 30 tokens per second).
| Metric | GLM-5.3 | GPT-5.2-Codex |
|---|---|---|
| BenchLeader Index | 61.4 | 60.8 |
| Agents & tools score | 65.2 | 63.5 |
| Composite score | 70.4 | 56.8 |
| Knowledge score | 71.0 | 63.2 |
| Long context score | 66.3 | 67.7 |
| Coding score | – | 55.7 |
| Instruction following score | – | 75.1 |
| Multimodal score | – | 60.7 |
| Blended price $/M | $2.15 | $4.81 |
| Output speed | 67 tok/s | 30 tok/s |
| Time to first answer | 33.0 s | 3.4 s |
| Context window | 1M | 400k |
| Terminal-Bench | – | 66.5% |
| APEX-Agents | – | 27.6% |
| Epoch Capabilities Index | 155.3 | – |
| LMArena WebDev | – | 1339 |
| LiveBench | 76.1% | 74.0% |
| LiveBench Reasoning | 85.8% | 77.7% |
| LiveBench Coding | 79.0% | 83.6% |
| LiveBench Agentic Coding | 60.9% | 49.4% |
| LiveBench Mathematics | 87.9% | 88.8% |
| LiveBench Data Analysis | 70.2% | 78.2% |
| LiveBench Language | 79.9% | 73.7% |
| AA Intelligence Index | 44.9 | 28.5 |
| IFBench | – | 77.6% |
| AA-LCR | 79.7% | 82.3% |
| MMMU-Pro | – | 76.3% |
| AA-Omniscience | 14.3 | -2.2 |
| Terminal-Bench Hard | – | 37.1% |
| GPQA Diamond (AA) | 91.7% | 89.9% |
| Humanity's Last Exam (AA) | 42.3% | 35.7% |
| SciCode (AA) | 59.0% | – |
| τ²-Bench Telecom (AA) | – | 92.1% |
| LiveCodeBench | – | 88.0% |
| SWE-Bench Pro | – | 41.0% |
| MCP Atlas | 84.2% | – |
| SWE-bench Verified (bash only) | – | 72.8% |
| SWE-bench Verified (any scaffold) | – | 72.8% |
Data as of 2026-09-17. Best configuration of each model; every score links to its source on the model pages.
GLM-5.3 vs GPT-5.2-Codex: questions
- Is GLM-5.3 better than GPT-5.2-Codex?
- GLM-5.3 and GPT-5.2-Codex are level on quality (61.4 vs 60.8). The BenchLeader Index combines every independent quality benchmark; GLM-5.3 is ahead overall as of 2026-09-17, but check the category scores for your use.
- Is GLM-5.3 better than GPT-5.2-Codex for agentic tasks?
- GLM-5.3 scores higher in agentic tasks (65 vs 64 on the category index, where 50 is average).
- Which is cheaper, GLM-5.3 or GPT-5.2-Codex?
- GLM-5.3 is cheaper: $2.15 against $4.81 per million tokens, blended at three input tokens per output token.
- Which is faster, GLM-5.3 or GPT-5.2-Codex?
- GLM-5.3 streams faster: 67 against 30 output tokens per second.
- Which has the larger context window?
- GLM-5.3 accepts more context: 1M against 400k tokens.