Models

Biel.ai supports models from OpenAI and Anthropic. Fast models are available on all plans, advanced models require a Business plan or above.

Available models

OpenAI

Model	Tier	Notes
GPT-5.6 Terra	Advanced	Latest generation. Strong at recognizing when to hand off to a human.
GPT-5.4	Advanced	Concise, focused answers.
GPT-5.1	Advanced	Strong all-around performance.
GPT-5.6 Luna (default)	Fast	Latest fast model. Better at escalating unanswerable questions than GPT-5.4 mini, at a similar speed.
GPT-5.4 mini	Fast	Tighter, faster answers than GPT-4.1 mini.
GPT-4.1 mini	Fast	Good balance of speed and quality.

Anthropic

Model	Tier	Notes
Claude Sonnet 5	Advanced	Latest generation. The best combination of speed and intelligence.
Claude Sonnet 4.6	Advanced	Strong on reasoning and coding.
Claude Haiku 4.5	Fast	Accurate and quick on general documentation.

Fast models work well for high-traffic sites and straightforward queries. Advanced models are better for highly technical content and detailed queries.

Which model should I pick?

Stick with the default (GPT-5.6 Luna) unless you have a reason to switch. It's our recommended model: tighter, faster answers, strong at staying on topic, reliable at offering human support when the docs can't answer, and available on every plan.

Switch when:

If you want...	Pick
A different fast model	Claude Haiku 4.5 or GPT-5.4 mini
In-depth answers for highly technical content	GPT-5.6 Terra, Claude Sonnet 5, or GPT-5.4

Change the model

important

Only Administrator or Maintainer roles can manage projects. See Manage roles.

1. In the Biel.ai dashboard, select your project.
2. Click Settings.
3. Open Chatbot in the left sidebar and, under LLM Settings > Select model, choose a model from the dropdown.
4. Click Save.

Data privacy

Chatbot interactions are opted out of third-party model training by default. Your data is not used to train or improve external AI models.