GPT-5.6 Terra vs GLM 5.3 Flash
GLM 5.3 Flash is 73.9× cheaper for typical traffic ; GPT-5.6 Terra scores higher on the Artificial Analysis intelligence index (42.1 vs 41.8).
Prices checked Oct 21, 2026
| GPT-5.6 Terra | GLM 5.3 Flash | |
|---|---|---|
| Developer | OpenAI | Z.ai |
| Input / 1M tokens | $2.00 | $0.041 |
| Output / 1M tokens | $12.00 | $0.12 |
| Cached input / 1M | $0.20 | $0.0037 |
| Context window | 1.05M | 1.05M |
| Max output | 128K | 944K |
| Intelligence index | 42.1 | 41.8 |
| Image input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning mode | Yes | Yes |
| Open weights | No | Yes |
Monthly cost for common workloads
| Workload | GPT-5.6 Terra | GLM 5.3 Flash |
|---|---|---|
| Customer chatbot 1,000 conversations a day, 8 turns each | $1,339 | $16.82 |
| Document Q&A (RAG) 500 questions a day over retrieved documents | $254 | $4.27 |
| Coding / tool-using agent 200 tasks a day, long tool-heavy contexts | $522 | $7.60 |
| Content generation 30 long articles a day | $32.40 | $0.381 |
| Classification / extraction 100,000 short items a day | $2,340 | $42.47 |
Estimates include cached-input discounts where a model offers them. Try your own numbers in the cost calculator.
Which one to choose
- Lowest cost: GLM 5.3 Flash — 73.9× cheaper on a 3:1 input/output mix.
- Longer documents: GPT-5.6 Terra reads up to 1.05M tokens at once.
- Capabilities: GPT-5.6 Terra — vision, tools, reasoning, JSON; GLM 5.3 Flash — vision, tools, reasoning, JSON, open weights.