Use a rule-based bot when you have a few simple, repeated questions and need fully predictable answers. Use an AI chatbot when visitors ask varied questions and the quality of the conversation affects whether they buy. Many good systems combine both: rules for sensitive steps, AI for open conversation.
How each works
A rule-based bot follows a script: buttons, menus and keyword matches that lead down fixed paths. It only handles what its designer anticipated.
An AI chatbot uses a language model to understand free-form text and write a reply, guided by instructions and your content. It can handle questions nobody planned for, but it needs guardrails.
Side by side
| Rule-based bot | AI chatbot | |
|---|---|---|
| Conversation | Fixed menus and keywords | Natural and open-ended |
| Predictability | Fully predictable | Needs guardrails and testing |
| Setup effort | Quick for simple flows | More design for persona and rules |
| Unexpected questions | Falls back to a menu | Can adapt, and hand off when unsure |
| Cost to run | Very low | Model usage cost per conversation |
| Risk of wrong answer | Low, answers are scripted | Present, so it needs controls |
Choose a rule-based bot if
- You have a handful of repeated questions with fixed answers.
- Answers must be exactly as written, for example legal or pricing text.
- Volume is high and you want near-zero running cost.
Choose an AI chatbot if
- Visitors ask varied questions before they buy.
- You want to qualify leads through conversation.
- The experience should feel like talking to a helpful person.
The combination that usually works
Put rules around the parts that must not vary, such as price, policy and legal wording, and let AI handle the open conversation. In Moonlight, our trip planner, the AI plans and chats freely, but a rule says it never quotes prices, because pricing stays with people. See how we built Moonlight.
For a deeper look at limits, read what an AI chatbot should never say, and see our comparison page.