Question: Is there a platform that offers a free plan to create and test a chatbot, with options to upgrade for more features and messages?

Chatbase offers a free tier with pay-as-you-go pricing that also includes premium features like lead generation, advanced analytics and support for multiple languages. Businesses can customize and embed chatbots directly into their websites or use APIs for interaction. The service can handle a variety of data sources and services like Slack and WhatsApp, so it's good for customer support and lead generation.

Another good option is Chat Data, which also offers a free tier. You can train and deploy chatbots with your own data and integrate with other services for a more personalized experience. Features include human support escalation, e-commerce store integration and HIPAA-compliant medical chat models. With a variety of backend options and add-ons, you can pay for what you need or downgrade.

If you want a no-code option, Libraria is a good option. It offers a free tier with one knowledge base and 50 GPT 3.5 messages per month. Libraria offers customizable chatbots, analytics and API/SDK integration, so it's good for e-commerce and internal team chatbots. It's designed to scale to businesses of all sizes, so it's a flexible and potentially economical AI chatbot option.