Model comparison
GLM-4.5-Air vs o3-pro
o3-pro is the stronger model overall, scoring 42.9 to 38.9 on the Noometry Index. GLM-4.5-Air costs 82× less per token, which makes it the better buy when o3-pro's lead doesn't matter for your workload.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. GLM-4.5-Air scores higher in 2 categories and o3-pro in 3 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in long context, where o3-pro leads 72.2 to 41.6.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 43% for GLM-4.5-Air and 72.1% for o3-pro.
- GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $20 / $80 for o3-pro.
- o3-pro accepts more context: 200K tokens versus 131K.
- GLM-4.5-Air has downloadable open weights; the other is API-only.
Side by side
| GLM-4.5-Air | o3-pro | |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 38.9 | 42.9 |
| Released | 2025-07-20 | 2025-06-10 |
| Weights | Open | Proprietary |
| Context window | 131K | 200K |
| Max output | 98K | 100K |
| Input $ / M tokens | $0.20 | $20 |
| Output $ / M tokens | $1.10 | $80 |
| Results tracked | 27 | 12 |
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Category by category
Coding o3-pro leads
GLM-4.5-Air: 33.3 (#259), o3-pro: 55.5 (#24)
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| GSO | 2.9% | — |
| WeirdML | — | 58.2% |
| LMArena Coding | 1397 | — |
Reasoning Too close to call
GLM-4.5-Air: 24.1 (#166), o3-pro: 23.8 (#171)
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| Kagi LLM Benchmark | 43% | 72.1% |
| ARC-AGI-2 | — | 4.9% |
| ARC-AGI-1 | — | 59.3% |
| LMArena Hard Prompts | 1379 | — |
| DTBench | — | 86.9% |
| LMCA | — | 38.5% |
| Epoch Capabilities Index | — | 147.42 |
| ForecastBench | 59.2 | — |
Math Not comparable
GLM-4.5-Air: 36.2 (#170), o3-pro: —
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| Omni-MATH | 39.1% | — |
| LMArena Math | 1396 | — |
Knowledge GLM-4.5-Air leads
GLM-4.5-Air: 35.0 (#191), o3-pro: 29.5 (#238)
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| Vectara Hallucination Rate | 9.3% | 23.3% |
| Humanity's Last Exam | 8.1% | — |
| MMLU-Pro | 76.2% | — |
| Confabulations | — | 14.2% |
| GPQA (HELM) | 59.4% | — |
| LMArena Expert | 1370 | — |
Multilingual Not comparable
GLM-4.5-Air: 49.1 (#135), o3-pro: —
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| LMArena Non-English | 1366 | — |
| LMArena Chinese | 1426 | — |
| LMArena French | 1399 | — |
| LMArena German | 1377 | — |
| LMArena Japanese | 1348 | — |
| LMArena Korean | 1308 | — |
| LMArena Russian | 1373 | — |
| LMArena Spanish | 1386 | — |
Instruction Following Not comparable
GLM-4.5-Air: 69.6 (#171), o3-pro: —
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| IFEval | 81.2% | — |
| LMArena Instruction Following | 1354 | — |
Long Context o3-pro leads
GLM-4.5-Air: 41.6 (#135), o3-pro: 72.2 (#1)
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1366 | — |
Writing & Preference o3-pro leads
GLM-4.5-Air: 55.9 (#139), o3-pro: 57.1 (#133)
| Benchmark | GLM-4.5-Air | o3-pro |
|---|---|---|
| LMArena Text | 1384 | — |
| LMArena Creative Writing | 1343 | — |
| Short-Story Creative Writing | — | 84.4% |
| WildBench | 78.9% | — |
| LMArena Multi-Turn | 1371 | — |
Frequently asked questions
Is GLM-4.5-Air better than o3-pro?
o3-pro is the stronger model overall, scoring 42.9 to 38.9 on the Noometry Index. GLM-4.5-Air costs 82× less per token, which makes it the better buy when o3-pro's lead doesn't matter for your workload.
Which is cheaper, GLM-4.5-Air or o3-pro?
GLM-4.5-Air is cheaper. It lists at $0.20 per million input tokens and $1.10 per million output tokens; o3-pro lists at $20 and $80.
Is GLM-4.5-Air or o3-pro better for coding?
o3-pro scores higher on coding benchmarks: 55.5 versus 33.3 in the Noometry coding category.
Which has the bigger context window?
o3-pro does, with 200K tokens against 131K.
How many benchmarks do GLM-4.5-Air and o3-pro share?
2 benchmarks have published results for both models. GLM-4.5-Air has 27 scored results on Noometry and o3-pro has 12.