Anthropic's Claude Fable 5.1 and Zhipu AI's GLM-5.3 compared on specs, pricing, and capabilities — as configured in AI Crucible ensembles.
| Specification | Claude Fable 5.1 | GLM-5.3 |
|---|---|---|
| Provider | Anthropic | Zhipu AI |
| API model ID | claude-fable-5-1 | zai-org/GLM-5.3 |
| Description | Anthropic's most capable model, for demanding reasoning and long-horizon agentic work, with 1M context and always-on adaptive thinking. | Z.AI's frontier open-weight model for coding and agentic work, with always-on reasoning and 1M context. |
| Context window | 1M tokens | 1M tokens |
| Max output tokens | 32,768 | 131,072 |
| Input cost ($/1M tokens) | $12.00 | $1.68 |
| Output cost ($/1M tokens) | $60.00 | $5.28 |
| Cache read cost ($/1M tokens) | $0.30 | $0.31 |
| Latency | high | medium |
| Reasoning model | Yes | Yes |
| Vision (image input) | Yes | No |
| Tool use | Yes | Yes |
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