$ diff claude-fable-5-1 glm-5-3-flash
Claude Fable 5.1 vs GLM-5.3-Flash
Values come from Claude Fable 5.1 and GLM-5.3-Flash, 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
- 1.0M
- weights
- open
- $/M in
- $0.15
- $/M out
- $0.5
What actually differs
- Context window
- GLM-5.3-Flash takes 1.0M against 1M — modestly more room in a single request.
- Input price
- GLM-5.3-Flash at $0.15/M against $10/M — 66.7× cheaper to feed. Standard rates: one of these labs also quotes a lower cached-input tier, which applies only when a prefix is reused — see the full spec below.
- Output price
- GLM-5.3-Flash at $0.5/M against $50/M — 100.0× cheaper to generate. Output dominates the bill on most agentic workloads, where the model writes far more than it reads.
- Weights
- GLM-5.3-Flash publishes weights (MIT); 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 6 days after GLM-5.3-Flash (2026-09-01 vs 2026-08-26).
Full spec
| Attribute | Claude Fable 5.1 | GLM-5.3-Flash |
|---|---|---|
| Developer | Anthropic | Z.ai |
| Released | 2026-09-01 | 2026-08-26 |
| Context window | 1M tokens | 1,048,576 (1M) |
| Pricing | $10/M input · $50/M output · cache reads $0.25/M | $0.15/M input · $0.03/M cached input · $0.50/M output |
| License | proprietary (API-only; no weight release) | MIT |
| Availability | Claude API as `claude-fable-5-1`; plan-tier access is disputed — see `## Conflicting Reports` | Hugging Face (open weights), Z.ai API |