Claude Fable 5.1 vs Hy4 preview: Specs & Benchmark Comparison
Claude Fable 5.1 is developed by Anthropic, while Hy4 preview comes from Tencent. Hy4 preview was released in August 2026, and Claude Fable 5.1 followed a month later in September 2026. Hy4 preview has a published size of about 770 billion parameters; Anthropic has not disclosed the parameter count of Claude Fable 5.1.
The two models share 2 published benchmarks. They split them evenly, 1 to 1. The widest gaps are on GDPval-AA, where Claude Fable 5.1 scores 61.8% against 55.9%; AutomationBench, where Hy4 preview scores 32.1% against 31.4%. Averaged across everything we track, Claude Fable 5.1 sits at 59.7% and Hy4 preview at 58.7%.
Claude Fable 5.1 is available through an API at $10 per million input tokens with a 1M-token context window. We do not track a hosted API for Hy4 preview, so pricing and context cannot be compared directly.
| Characteristic | Claude Fable 5.1 | Hy4 preview |
|---|---|---|
| Company | Anthropic | Tencent |
| Release Date | September 1, 2026 | August 28, 2026 |
| Parameters | — | 770B |
| Multimodal | Yes | No |
| Context (input) | 1.0M | — |
| Context (output) | 128K | — |
| Input Price / 1M | $10.00 | — |
| Output Price / 1M | $50.00 | — |
| Average Score | 59.7% | 58.7% |
| Benchmarks | ||
| GDPval-AA | 61.8% | 55.9% |
| AutomationBench | 31.4% | 32.1% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Claude Fable 5.1 — 0.6, Hy4 preview — 0.6.
Both models were released around the same time: 9/1/2026 and 8/28/2026.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5.1 or Hy4 preview?
Which model is cheaper — Claude Fable 5.1 or Hy4 preview?
Which has a larger context window — Claude Fable 5.1 or Hy4 preview?
The Claude Fable 5.1 and Hy4 preview comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Fable 5.1 or Hy4 preview page. See also the complete list of AI model comparisons.