Gradio

Gradio turns a Python function into a web interface with a few lines of code. You get input widgets, outputs, sharing links and an auto-generated API, which makes it popular for demoing models.

It powers the demos on Hugging Face and many image-generation UIs. It now also supports building MCP servers and chatbots.

For data scientists who want to show a model without learning front-end development, it is hard to beat.