Model comparison
GLM-4.5-Air vs GPT-5 Nano
GLM-4.5-Air is the stronger model overall, scoring 38.9 to 33.5 on the Noometry Index. GPT-5 Nano costs 3.1× less per token, which makes it the better buy when GLM-4.5-Air's lead doesn't matter for your workload.
Last verified . 24 shared benchmarks.
Summary
- They share 24 benchmarks with published results for both. GLM-4.5-Air scores higher in 5 categories and GPT-5 Nano in 3 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where GLM-4.5-Air leads 55.9 to 39.1.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 43% for GLM-4.5-Air and 62.2% for GPT-5 Nano.
- GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $0.20 / $1.10 for GLM-4.5-Air.
- GPT-5 Nano accepts more context: 400K tokens versus 131K.
- GLM-4.5-Air has downloadable open weights; the other is API-only.
Side by side
| GLM-4.5-Air | GPT-5 Nano | |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 38.9 | 33.5 |
| Released | 2025-07-20 | 2025-08-07 |
| Weights | Open | Proprietary |
| Context window | 131K | 400K |
| Max output | 98K | 128K |
| Input $ / M tokens | $0.20 | $0.05 |
| Output $ / M tokens | $1.10 | $0.40 |
| Results tracked | 27 | 49 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Too close to call
GLM-4.5-Air: 33.3 (#259), GPT-5 Nano: 33.6 (#254)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| LMArena Coding | 1397 | 1351 |
| SWE-bench Verified (bash only) | — | 34.8% |
| GSO | 2.9% | — |
| WeirdML | — | 38.1% |
| ALE-Bench | — | 718.67 |
Agentic & Tool Use Not comparable
GLM-4.5-Air: —, GPT-5 Nano: 25.8 (#106)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| Terminal-Bench | — | 21.8% |
| Berkeley Function Calling Leaderboard | — | 51.5% |
Reasoning GLM-4.5-Air leads
GLM-4.5-Air: 24.1 (#166), GPT-5 Nano: 16.3 (#306)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| Kagi LLM Benchmark | 43% | 62.2% |
| LMArena Hard Prompts | 1379 | 1328 |
| ForecastBench | 59.2 | 59.1 |
| ARC-AGI-2 | — | 2.6% |
| ARC-AGI-1 | — | 20.7% |
| Chess Puzzles | — | 27% |
| Mystery Game Puzzles | — | 9% |
| DTBench | — | 62.7% |
| LMCA | — | 7.9% |
| Epoch Capabilities Index | — | 139.38 |
Math GLM-4.5-Air leads
GLM-4.5-Air: 36.2 (#170), GPT-5 Nano: 29.4 (#241)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| Omni-MATH | 39.1% | 54.6% |
| LMArena Math | 1396 | 1317 |
| FrontierMath (Tiers 1-3) | — | 20% |
| FrontierMath Tier 4 | — | 2.4% |
| OTIS Mock AIME 2024-2025 | — | 81.1% |
| ProofBench | — | 12% |
| MATH Level 5 | — | 95.2% |
| FrontierMath (Feb 2025 set) | — | 8.3% |
| FrontierMath Tier 4 (v1) | — | 2.1% |
Knowledge Too close to call
GLM-4.5-Air: 35.0 (#191), GPT-5 Nano: 35.9 (#178)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| MMLU-Pro | 76.2% | 77.8% |
| Vectara Hallucination Rate | 9.3% | 10.5% |
| GPQA (HELM) | 59.4% | 67.9% |
| LMArena Expert | 1370 | 1321 |
| GPQA Diamond | — | 69.4% |
| Humanity's Last Exam | 8.1% | — |
| SimpleQA Verified | — | 11.7% |
Multimodal Not comparable
GLM-4.5-Air: —, GPT-5 Nano: 31.3 (#108)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| LMArena Vision | — | 1159 |
| VPCT | — | 37.2% |
Multilingual GLM-4.5-Air leads
GLM-4.5-Air: 49.1 (#135), GPT-5 Nano: 45.3 (#172)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| LMArena Non-English | 1366 | 1313 |
| LMArena Chinese | 1426 | 1356 |
| LMArena German | 1377 | 1327 |
| LMArena Japanese | 1348 | 1226 |
| LMArena Korean | 1308 | 1269 |
| LMArena Russian | 1373 | 1296 |
| LMArena Spanish | 1386 | 1360 |
| LMArena French | 1399 | — |
Instruction Following GPT-5 Nano leads
GLM-4.5-Air: 69.6 (#171), GPT-5 Nano: 75.0 (#79)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| IFEval | 81.2% | 93.2% |
| LMArena Instruction Following | 1354 | 1306 |
Long Context GLM-4.5-Air leads
GLM-4.5-Air: 41.6 (#135), GPT-5 Nano: 31.3 (#281)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| LMArena Longer Query | 1366 | 1312 |
| Fiction.LiveBench | — | 44.4% |
Writing & Preference GLM-4.5-Air leads
GLM-4.5-Air: 55.9 (#139), GPT-5 Nano: 39.1 (#249)
| Benchmark | GLM-4.5-Air | GPT-5 Nano |
|---|---|---|
| LMArena Text | 1384 | 1320 |
| LMArena Creative Writing | 1343 | 1249 |
| WildBench | 78.9% | 80.6% |
| LMArena Multi-Turn | 1371 | 1311 |
| EQ-Bench Creative Writing | — | 705 |
Frequently asked questions
Is GLM-4.5-Air better than GPT-5 Nano?
GLM-4.5-Air is the stronger model overall, scoring 38.9 to 33.5 on the Noometry Index. GPT-5 Nano costs 3.1× less per token, which makes it the better buy when GLM-4.5-Air's lead doesn't matter for your workload.
Which is cheaper, GLM-4.5-Air or GPT-5 Nano?
GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; GLM-4.5-Air lists at $0.20 and $1.10.
Is GLM-4.5-Air or GPT-5 Nano better for coding?
They score almost the same on coding (33.3 vs 33.6); test both on your own repository before choosing.
Which has the bigger context window?
GPT-5 Nano does, with 400K tokens against 131K.
How many benchmarks do GLM-4.5-Air and GPT-5 Nano share?
24 benchmarks have published results for both models. GLM-4.5-Air has 27 scored results on Noometry and GPT-5 Nano has 49.