Fern vs GitBook (2026): which should you pick?

Pick Fern if

• Fits if you maintain an OpenAPI spec and want a hosted docs site at no cost to start
• Works for small API teams that want an API explorer and a custom domain on the free plan

Look elsewhere if

• Skip it if you need SSO or SCIM, which are Enterprise only
• Tight if you outgrow 1 site, 1,000 pages or 10 members, as the next step is a sales quote
• Not for you if you want to remove Fern branding or add custom CSS and JavaScript without Enterprise
• Watch out: SDK pricing sits on a separate tab that this listing did not read

Pick GitBook if

• Fits if you publish product or API docs and want changes reviewed and merged like code
• Works for a solo writer, since one user gets unlimited basic sites for free

Look elsewhere if

• Pricey if your team is big, as every user is $12 a month on top of $65 a site, read-only members too
• Skip it if you need docs behind a login on a small budget, because that starts at $249 a site
• Tight if you lean on the AI answers, since Essential's 2,000 credits cover about 100 a month and packs start at $47.50
• Tight if you're staying free: one user, no custom domain, no AI Assistant, no live co-editing, and the Agent at 10 messages a week
• Not for you if you need SAML SSO without an Enterprise contract, or a desktop or phone app

Fern

• Only two documentation plans are listed, Free and a sales-only Enterprise, so there is no published mid-tier price.
• SSO, SCIM, custom CSS and JavaScript, removing Fern branding and self-hosting are Enterprise only.
• The Free plan is limited to 1 site, 1,000 pages and 10 members.
• SDK pricing was not read for this listing; the pricing page has a separate SDKs tab.

GitBook

• Paid plans combine a per-site fee with $12 per user / month, and guests and read-only members cost the same as other members.
• AI answers and translations use credits: Essential includes 2,000 a month and Ultimate 10,000, at 20 per relevant answer. Extra packs start at $47.50 a month for 5,000.
• The Free plan covers a single user and leaves out custom domains, the AI Assistant and real-time collaboration.
• SAML SSO is limited to Enterprise; AI Assistant Chat, adaptive content and authenticated access need Ultimate at $249 per site / month.

Fern

Docs from API specs

Supports OpenAPI, AsyncAPI, gRPC, GraphQL, OpenRPC and Arazzo, plus Markdown guides and changelogs.

API explorer

A try-it-out explorer with an option to fill in the visitor's API key.

Web editor and docs-as-code

Pages can be edited in a web editor or kept as files in a repository.

AI features

Ask Fern search, an AI writing agent, AI translations, an llms.txt file and an MCP server are on the pricing page.

SDK generation

Client libraries are generated from the same API definition; the SDK pricing is a separate tab.

GitBook

Block-based editor

A visual editor built from blocks, including custom ones. Added users collaborate through change requests and content reviews before edits are published.

Git Sync

Two-way sync with GitHub or GitLab lets a team branch, review and merge documentation like a pull request. It is included on every plan, the Free one too.

Published docs sites

Sites get unlimited traffic and preview deployments on every plan. Custom domains, branding and redirects start on Essential; sections and site groups need Ultimate.

AI Assistant, paid for in credits

On Essential, AI Assistant Ask gives readers short answers in the search box. Ultimate adds Assistant Chat, a sidebar that can draw on connected sources. Each relevant answer uses 20 AI credits.

GitBook Agent

Writes, edits and updates documentation and flags content that no longer matches the product. Free accounts are limited to 10 messages a week.

API docs and LLM-ready output

OpenAPI specifications become interactive API playgrounds. Every site also gets llms.txt files, Markdown versions of pages and its own MCP server.

Fern

• Free$0

  10 members, 1,000 pages, 250 AI credits and 2,000 page generations per month, custom domain and subpath, API explorer, Ask Fern and MCP server.

• EnterpriseCustom

  Adds SSO, SCIM and advanced RBAC, multiple repos and docs sites, custom CSS, JavaScript and React, advanced analytics, self-hosting and an uptime SLA. Sold through sales.

GitBook

• Free$0

  For individuals: 1 user, block-based editor, GitHub or GitLab sync, interactive API playgrounds, preview deployments and LLM optimizations.

• Essential$65

  per site / month, billed annually, plus $12 per user / month

  Team collaboration, a custom domain, advanced branding, analytics, user feedback, redirects and 2,000 AI credits a month for AI Assistant Ask. $79 a site billed monthly.

• Ultimate$249

  per site / month, billed annually, plus $12 per user / month

  10,000 AI credits a month, AI Assistant Chat, AI insights, adaptive content, authenticated access, site sections and channels for Slack, Linear and GitHub. $299 billed monthly.

• EnterpriseCustom

  SAML SSO, migration service, custom integrations, dedicated support, custom contracts and invoicing, and Git Sync IP allowlisting.

Fern

No public discounts listed.

GitBook

• Annual discount

  2 months free with annual billing

  Billed annually, Essential is $65 and Ultimate $249 a site a month, against $79 and $299 billed monthly; users are $12 against $15. Annual plans are paid up front and not refunded mid-term.

• Nonprofit

  Free Community plan for non-profits

  Eligible non-profit organizations can apply for the free Community plan, which includes all Ultimate plan features except SAML SSO.

• Education

  Free Community plan for education groups

  Education-related groups such as student, lab or course groups can apply for the Community plan. Schools, colleges and universities themselves are excluded.

• Other savings

  Free Community plan for open source

  Open source organizations that need to collaborate beyond the Free plan can apply for the Community plan at no cost, with all Ultimate features except SAML SSO.