OpenAI: GPT-5.6 Terra Pro vs Z.ai: GLM 5.3 Flash
On input price, Z.ai: GLM 5.3 Flash is ~13.3× cheaper. Verified 2026-10-21.
Verdict
On blended price (3:1 input:output), Z.ai: GLM 5.3 Flash is ~18.9× cheaper ($0.150/$0.500 vs $2.00/$12.00 per 1M tokens).
Pricing
Per-million-token list prices, verified 2026-10-21. Green marks the better value.
| Metric | OpenAI: GPT-5.6 Terra Pro | Z.ai: GLM 5.3 Flash |
|---|---|---|
| Input / 1M | $2.00 | $0.150 |
| Output / 1M | $12.00 | $0.500 |
| Cache read / 1M | $0.200 | $0.030 |
| Blended (3:1) | $4.50/1M | $0.237/1M |
| Estimated monthly cost | OpenAI: GPT-5.6 Terra Pro | Z.ai: GLM 5.3 Flash |
|---|---|---|
| Chatbot10,000 reqs · 800/400 tok | $64.00 | $3.20 |
| Coding agent5,000 reqs · 8000/2000 tok | $200.00 | $11.00 |
| RAG pipeline30,000 reqs · 4000/500 tok | $420.00 | $25.50 |
Plug in your own numbers in the calculator, or paste a real bill into the Bill Shredder.
Specifications & capabilities
| Metric | OpenAI: GPT-5.6 Terra Pro | Z.ai: GLM 5.3 Flash |
|---|---|---|
| Context window | 1.1M | 1.0M |
| Max output | 128K | 944K |
| Vision input | ✓ | ✓ |
| Tool calling | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
Quality
Intelligence Index by Artificial Analysis (independent evaluations, 0–100).
Verified intelligence scores aren't available for both models yet. See the full leaderboard.
Performance
Measured by Artificial Analysis on live endpoints.
Speed measurements aren't available for both models yet.
Provider
Infrastructure metrics for the organizations behind these models.
| Metric | OpenAI | Z.ai (GLM) |
|---|---|---|
| Listed endpoints | 12 | 4 |
| Reliability | 99.9% | 99.2% |
| Avg latency | 450 ms | 500 ms |
| Pricing tiers | standard, batch, provisioned | standard, free, batch |
Full details: OpenAI: GPT-5.6 Terra Pro pricing · Z.ai: GLM 5.3 Flash pricing