GitBook is a hosted documentation platform priced per site plus per user, with bi-directional Git Sync to GitHub or GitLab. Pages here cover replacing it with self-hosted Wiki.js, BookStack or Docmost.
Comparing GitBook with Wiki.js for documentation kept in Git: Wiki.js Git storage that syncs both ways, Markdown and visual editors, authentication modules including SAML at no extra cost, public and private docs, and the stable 2.x line against the 3.0 beta.
For internal and product documentation in GitBook: BookStack's shelves, books, chapters and pages, WYSIWYG and Markdown editing, SAML, OIDC and LDAP sign-in on the free MIT release, and what is lost without GitBook's Git workflow and published docs sites.
Moving GitBook spaces to Wiki.js through Git: syncing GitBook content to a GitHub or GitLab repository of Markdown, connecting Wiki.js Git storage to it, cleaning GitBook-specific blocks, mapping navigation and redirects, and cutting over the docs domain.
Cost of ownership by component: GitBook's per-site fee plus per-user fee and Enterprise-only SAML, against Wiki.js or BookStack with no license fee, a server and PostgreSQL or MySQL, a CDN for public docs, migration and maintenance.
Using GitBook's Git Sync, available on every plan, to get all content out as Markdown in GitHub or GitLab: who can enable it, what syncs and what does not, such as site settings and integrations, and how to check the repository is complete before ending the contract.
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