Mintlify is a documentation service, as compared to Fumadocs, it offers a free tier but isn't completely free and open source.
Fumadocs is not as powerful as Mintlify, for example, the OpenAPI integration of Mintlify.
As the creator of Fumadocs, I wouldn't recommend switching to Fumadocs from Mintlify if you're satisfied with the current way you build docs.
However, I believe Fumadocs is a suitable tool for all Next.js developers who want to have elegant docs.
Since Fumadocs is built on the top of Next.js, you'll have to start the Next.js dev
server every time to review changes. And boilerplate code is relatively more
compared to Docusaurus. For a simple docs, Docusaurus might be a better choice
if you don't need any Next.js specific functionality.
You can easily achieve many things with plugins. Although the flexibility of Fumadocs is high, their
eco-system is larger and maintained by many contributors.
For most of the web applications, vanilla React.js is no longer enough.
Nowadays, we also wish to have a blog, a showcase page, a FAQ page, etc. With a
fancy UI that's breathtaking, in these cases, Fumadocs can help you build the
docs easier, with less boilerplate.
More and more advanced features are rolling out. We currently support
multiple searching solutions including Algolia Search. A good UI and user
experience is always our priority, welcome to give us feedback via Github
discussions!