Based on our record, Docsie seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
If you need just the customer-facing knowledge base there are a lot of tools out there that can build the website for you: archbee.io, docsie.io, docusaurus. Source: about 3 years ago
I looked at https://docsie.io/, and it seems like it would work perfectly, except I would have to pay a ton to have more than 3 pages on it (if I understand the pricing). Source: about 4 years ago
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.
DocFX - A documentation generation tool for API reference and Markdown files!
Documize - Enterprise-grade wiki and knowledge management platform
MkDocs - Project documentation with Markdown.
HackMD - Fast and flexible, real-time collaborative markdown, inspired by Hackpad.