Best/worst documentation website UIs?

Best for me would be like Expo.io and Facebook’s help site. Worst would be Google, Varnish Cache and lots more. Those are the most popular ones I can think of off the top of my head. I may or may not have had a period of time where I literally found about 200 documentation sites and chose the ones I liked the most! It was a while back though. Really, documentation is best when it actually answers questions and tells you stuff in order. Docusuarus seems to encourage that style with its UI. Microsoft’s documentation UI is bad, but has great information. The opposite is true with Cloudflare’s documentation. Oh, Fastly also has a terrible documentation.

For me it's all about adhering to conventions of docs sites. I've been exploring Docusaurus [1] over the last week and I think they hit all of the important conventions. Breadcrumb at top. Site nav on left. Page nav on right. Dropdowns for language and version on the site header.

[1] https://docusaurus.io/docs