OpenLuxClaude Fable 5.1 vs Gemini 3.1 Pro (preview)
Claude Fable 5.1 and Gemini 3.1 Pro (preview) both run on OpenLux behind one OpenAI-compatible endpoint. Claude Fable 5.1 is metered at $1.765 per 1M tokens (-82% vs official rates); Gemini 3.1 Pro (preview) at $0.1471 per 1M tokens (-92% vs official rates). Gemini 3.1 Pro (preview) is the lower-cost option per unit — about 92% cheaper on the same OpenLux endpoint. This page compares their rates, strengths and best-fit workloads so you can route each request to the right model.
The short version
In practice the two models are complements, not substitutes: Claude Fable 5.1 suits workloads that need agents and apps that call tools or functions, prompts that include images, charts or screenshots. Gemini 3.1 Pro (preview) is the better fit when you need multimodal questions that benefit from extended thinking, production chat and assistant workloads. Both are called with the same OpenLux key, so switching between them is a one-field change to the model name.
Choose Claude Fable 5.1 when
- You need agents and apps that call tools or functions.
- You need prompts that include images, charts or screenshots.
Choose Gemini 3.1 Pro (preview) when
- You need multimodal questions that benefit from extended thinking.
- You need production chat and assistant workloads.
- Unit cost is the deciding factor for this workload.
Rates on OpenLux
| Model | Provider | Rate | Discount |
|---|---|---|---|
| Claude Fable 5.1 | Anthropic | $1.765 per 1M tokens | -82% |
| Gemini 3.1 Pro (preview) | $0.1471 per 1M tokens | -92% |
Rates follow official provider pricing and are billed in USD. See the full catalogue and pricing plans for credit allowances.
One snippet, two models
Claude Fable 5.1 and Gemini 3.1 Pro (preview) share the same OpenAI-compatible request shape. Run the same code against both and compare the answers on your own workload.
from openai import OpenAI
client = OpenAI(
api_key="sk-openlux-...",
base_url="https://openlux.lol/v1",
)
for model in ["claude-fable-5-1", "gemini-3.1-pro-preview"]:
resp = client.chat.completions.create(
model=model,
messages=[{"role": "user", "content": "Summarise this release note for me."}],
)
print(model, "->", resp.choices[0].message.content)Any OpenAI SDK works the same way — see the docs for streaming, tools and error codes.
Claude Fable 5.1 vs Gemini 3.1 Pro (preview) questions
How much do Claude Fable 5.1 and Gemini 3.1 Pro (preview) cost on OpenLux?
Claude Fable 5.1 is metered pay as you go at $1.765 per 1M tokens, a -82% discount on official list pricing. Gemini 3.1 Pro (preview) is metered at $0.1471 per 1M tokens, a -92% discount. There is no subscription requirement: usage is billed in USD and every request is visible in the console.
Can I call Claude Fable 5.1 and Gemini 3.1 Pro (preview) with the same API key?
Yes. Both models sit behind the same OpenAI-compatible endpoint at https://openlux.lol/v1. Keep the same key and change only the "model" field to switch between claude-fable-5-1 and gemini-3.1-pro-preview — request and response shapes stay identical.
Which is cheaper, Claude Fable 5.1 or Gemini 3.1 Pro (preview)?
Gemini 3.1 Pro (preview) costs less per unit: $0.1471 per 1M tokens versus $1.765 per 1M tokens, about 92% lower for the same volume. Over a month of production traffic the difference compounds, and the console shows cost per request in real time.
When should I pick Claude Fable 5.1 over Gemini 3.1 Pro (preview)?
In practice the two models are complements, not substitutes: Claude Fable 5.1 suits workloads that need agents and apps that call tools or functions, prompts that include images, charts or screenshots. Gemini 3.1 Pro (preview) is the better fit when you need multimodal questions that benefit from extended thinking, production chat and assistant workloads. Both are called with the same OpenLux key, so switching between them is a one-field change to the model name.
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Route every request to the right model
OpenLux keeps Claude Fable 5.1, Gemini 3.1 Pro (preview) and every other model behind one key, one endpoint and one bill. Start with free trial credit and switch models without touching your code.