Model comparison
Claude Fable 5.1 vs GLM-5.1
Claude Fable 5.1 (Anthropic) and GLM-5.1 (Z.ai) side by side: what each costs per million tokens through Rapid Router, how much context each takes, what each supports, and where independent benchmarks place them. Same API, same key; switching is a one-string change.
| Claude Fable 5.1 | GLM-5.1 | |
|---|---|---|
| Input price per 1M | $10.00 | $1.05 |
| Output price per 1M | $50.00 | $3.50 |
| Context window | 1M tokens | 200K tokens |
| Max output | 128K tokens | 131K tokens |
| Input types | text, image, pdf | text |
| Capabilities | tools, JSON, vision, reasoning | tools, JSON, reasoning |
| Author | Anthropic | Z.ai |
What a month costs on each
| Workload | Claude Fable 5.1 | GLM-5.1 |
|---|---|---|
| Chatbot month (15M in, 4M out) | $350.00 | $29.75 |
| RAG month (40M in, 3M out) | $550.00 | $52.50 |
| Coding month (60M in, 10M out) | $1100.00 | $98.00 |
On a typical 75/25 input-output mix, GLM-5.1 costs less (about 92% less than Claude Fable 5.1). Claude Fable 5.1 takes the longer prompt at 1M tokens. Try your own numbers in the cost calculator.
Call either one
curl https://rapidrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $RAPIDROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "anthropic/claude-fable-5-1", "messages": [{"role": "user", "content": "Hello"}]}'
# the other one: change the model string
-d '{"model": "z-ai/glm-5.1", ...}'Common questions
Which is cheaper, Claude Fable 5.1 or GLM-5.1?
GLM-5.1 is cheaper on a typical mix of 75% input and 25% output tokens, by about 92%. Through Rapid Router both are billed at the provider list price per million tokens.
Which has the larger context window?
Claude Fable 5.1, at 1M tokens. GLM-5.1 offers 200K tokens.
Can I switch between Claude Fable 5.1 and GLM-5.1 without changing code?
Yes. Both are callable at https://rapidrouter.ai/api/v1 with the same OpenAI-compatible request; only the model string changes (anthropic/claude-fable-5-1 or z-ai/glm-5.1).
How do I pay for Claude Fable 5.1 or GLM-5.1?
Top up a Rapid Router balance by card in US dollars, and both models debit that balance per request.
More Claude models: Anthropic API pricing · More GLM: Z.ai API pricing