Head to head
Anthropic: Claude Fable 5.1 vs Z.ai: GLM 5.3 Flash
Live prices, context windows, capabilities, and measured quality — updated continuously.
Side by side
| Metric | Anthropic: Claude Fable 5.1 Anthropic | Z.ai: GLM 5.3 Flash Z Ai |
|---|---|---|
| Input $/M tokens | $10.00 | $0.075 |
| Output $/M tokens | $50.00 | $0.250 |
| Context window | 1.0M | 1.3M |
| Max output | 128K | 131K |
| WM Score | 92 | 89 |
| Benchmark quality | 97.7 | 83.1 |
| Hosts serving it | 4 | 24 |
| Throughput (tok/s) | 51 | 89 |
| Latency (ms) | 2770 | 490 |
| Vision | ||
| Tools | ||
| Reasoning | ||
| JSON mode |
Which should you pick?
Z.ai: GLM 5.3 Flash costs less per million input tokens — about 133.3× cheaper than Anthropic: Claude Fable 5.1. Anthropic: Claude Fable 5.1 scores higher on measured quality. Z.ai: GLM 5.3 Flash takes a larger context window, which matters for long documents or big codebases. Prices here are live list prices; the same model can cost less on a different host, so check the model page for the cheapest offering.