Model comparison
GLM-4.5 vs GPT-5-Codex
GLM-4.5 is the stronger model overall, scoring 41.4 to 37.3 on the Noometry Index.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. GLM-4.5 scores higher in 0 categories and GPT-5-Codex in 2 categories; one gap is clear of the uncertainty.
- The biggest single-benchmark swing is WeirdML: 40.6% for GLM-4.5 and 54.5% for GPT-5-Codex.
- GLM-4.5 is cheaper at $0.60 / $2.20 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- GPT-5-Codex accepts more context: 400K tokens versus 131K.
- GLM-4.5 has downloadable open weights; the other is API-only.
Side by side
| GLM-4.5 | GPT-5-Codex | |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 41.4 | 37.3 |
| Released | 2025-07-27 | 2025-09-15 |
| Weights | Open | Proprietary |
| Context window | 131K | 400K |
| Max output | 98K | 128K |
| Input $ / M tokens | $0.60 | $1.25 |
| Output $ / M tokens | $2.20 | $10 |
| Results tracked | 27 | 3 |
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Category by category
Coding Too close to call
GLM-4.5: 41.1 (#121), GPT-5-Codex: 41.9 (#100)
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| WeirdML | 40.6% | 54.5% |
| SWE-bench Verified (bash only) | 54.2% | — |
| LMArena Coding | 1434 | — |
| ALE-Bench | 344.82 | — |
| AlgoTune | 1.52 | — |
Agentic & Tool Use Not comparable
GLM-4.5: —, GPT-5-Codex: 30.8 (#66)
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| Terminal-Bench | — | 44.3% |
Reasoning GPT-5-Codex leads
GLM-4.5: 27.7 (#99), GPT-5-Codex: 30.0 (#80)
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| Kagi LLM Benchmark | 57.9% | 70.3% |
| LMArena Hard Prompts | 1430 | — |
Math Not comparable
GLM-4.5: 36.3 (#119), GPT-5-Codex: —
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| LMArena Math | 1427 | — |
Knowledge Not comparable
GLM-4.5: 35.5 (#172), GPT-5-Codex: —
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| Humanity's Last Exam | 8.3% | — |
| Confabulations | 11.3% | — |
| LMArena Expert | 1433 | — |
Multilingual Not comparable
GLM-4.5: 53.0 (#74), GPT-5-Codex: —
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| LMArena Non-English | 1417 | — |
| LMArena Chinese | 1465 | — |
| LMArena French | 1423 | — |
| LMArena German | 1406 | — |
| LMArena Japanese | 1416 | — |
| LMArena Korean | 1382 | — |
| LMArena Russian | 1414 | — |
| LMArena Spanish | 1454 | — |
Instruction Following Not comparable
GLM-4.5: 74.3 (#100), GPT-5-Codex: —
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| LMArena Instruction Following | 1405 | — |
Long Context Not comparable
GLM-4.5: 38.2 (#196), GPT-5-Codex: —
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| Fiction.LiveBench | 58.3% | — |
| LMArena Longer Query | 1413 | — |
Writing & Preference Not comparable
GLM-4.5: 57.7 (#121), GPT-5-Codex: —
| Benchmark | GLM-4.5 | GPT-5-Codex |
|---|---|---|
| LMArena Text | 1430 | — |
| LMArena Creative Writing | 1395 | — |
| Short-Story Creative Writing | 73.4% | — |
| EQ-Bench Creative Writing | 1343 | — |
| LMArena Multi-Turn | 1415 | — |
Frequently asked questions
Is GLM-4.5 better than GPT-5-Codex?
GLM-4.5 is the stronger model overall, scoring 41.4 to 37.3 on the Noometry Index.
Which is cheaper, GLM-4.5 or GPT-5-Codex?
GLM-4.5 is cheaper. It lists at $0.60 per million input tokens and $2.20 per million output tokens; GPT-5-Codex lists at $1.25 and $10.
Is GLM-4.5 or GPT-5-Codex better for coding?
They score almost the same on coding (41.1 vs 41.9); test both on your own repository before choosing.
Which has the bigger context window?
GPT-5-Codex does, with 400K tokens against 131K.
How many benchmarks do GLM-4.5 and GPT-5-Codex share?
2 benchmarks have published results for both models. GLM-4.5 has 27 scored results on Noometry and GPT-5-Codex has 3.