GLM-4.5 vs GPT-5 Nano
API pricing, benchmark indices and specs — updated 19 October 2026.
openai · B · API-only
Input / 1M
$0.05
Output / 1M
$0.40
AA index
13
proprietary · 400K context
Specification comparison
Differences are highlighted; identical values are muted.
| Specification | GLM-4.5 | GPT-5 Nano |
|---|---|---|
| Deployment | Open weights · also via API | API-only (closed weights) |
| Parameters | 358.3 B | n/a — API-only |
| Architecture | Glm4MoeForCausalLM | n/a — API-only |
| Context length | 131,072 | 400,000 |
| Licence | mit | Proprietary |
| Commercial use | Allowed | Per API terms |
| Languages | 2 | n/a — API-only |
| Downloads 30d | 113,929 | n/a — API-only |
| Downloads all time | 1.2 M | n/a — API-only |
| Quantizations on the Hub | SAFETENSORS | n/a — API-only |
| Gated | No | n/a — API-only |
| First seen on the Hub | 2025-07-20 | n/a — API-only |
| API input price / 1M tokens | $0.60 | $0.05 |
| API output price / 1M tokens | $2.20 | $0.40 |
| Est. cost per 1M input + 1M output tokens | $2.80 | $0.45 |
| Cached input / 1M tokens | $0.11 | $0.005 |
| AA Intelligence Index | 12.8 | 13 |
| AA Coding Index | — | — |
| AA Agentic Index | — | — |
| Max output tokens | 98,304 | 128,000 |
| API providers | 1 | 2 |
| Tool calling | Yes | Yes |
| Reasoning mode | Yes | Yes |
API cost
Estimated cost of 1M input + 1M output tokens via OpenRouter
GLM-4.5
$2.80
GPT-5 Nano
$0.45
GPT-5 Nano is 6.2× cheaper at list price.
VRAM side by side
On RTX 4090 · 24 GB · 8K context unless noted
GLM-4.5 · fp16 @ 128K ctx
1,648.9 GB / 24 GB