$ diff claude-fable-5-1 hy4-preview
Claude Fable 5.1 vs Hy4 preview
Values come from Claude Fable 5.1 and Hy4 preview, where each is cited to its source. This page states no benchmark result and ranks neither model — it puts two published specifications next to each other. Where a lab has not published a figure, the row says so rather than guessing.
AnthropicClaude Fable 5.1
- context
- 1M
- weights
- closed
- $/M in
- $10
- $/M out
- $50
- context
- 1M
- weights
- open
- $/M in
- $0.834
- $/M out
- $2.501
What actually differs
- Context window
- Identical — both accept 1M tokens, so context length is not a reason to pick either.
- Input price
- Hy4 preview at $0.834/M against $10/M — 12.0× cheaper to feed.
- Output price
- Hy4 preview at $2.501/M against $50/M — 20.0× cheaper to generate. Output dominates the bill on most agentic workloads, where the model writes far more than it reads.
- Weights
- Hy4 preview publishes weights (Apache-2.0); Claude Fable 5.1 is API-only. That decides self-hosting, air-gapped deployment and fine-tuning before any capability question does.
- Recency
- Claude Fable 5.1 shipped 4 days after Hy4 preview (2026-09-01 vs 2026-08-28).
Full spec
| Attribute | Claude Fable 5.1 | Hy4 preview |
|---|---|---|
| Developer | Anthropic | Tencent |
| Released | 2026-09-01 | 2026-08-28 |
| Context window | 1M tokens | over 1,000,000 |
| Pricing | $10/M input · $50/M output · cache reads $0.25/M | $0.834/M input · $2.501/M output |
| License | proprietary (API-only; no weight release) | Apache-2.0 |
| Availability | Claude API as `claude-fable-5-1`; plan-tier access is disputed — see `## Conflicting Reports` | Hugging Face (BF16 + FP8), ModelScope, GitCode, CNB, Tencent Cloud TokenHub, OpenRouter, WorkBuddy, CodeBuddy, Yuanbao, ima |