
Mintlify
Docusaurus
Archbee.io
ReadMe
Slite
Atlassian Bitbucket Server
MkDocs
Modern Publishing, Simply taking your books from ideas to finished, polished books.

Coassemble
Trainn.co
Build courses by API, drop them into your product with one iframe, and get told who finished. No portal, no learner accounts, priced per course view.

Which is more popular?
Based on our record, GitBook seems to be more popular. It has been mentioned 6 times since March 2021.
Website, pricing, platforms and company facts side by side.
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|---|---|---|
| Website | gitbook.com | underlayerhq.com |
| Pricing | ||
| Company | — | Startup from the United Arab Emirates · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of GitBook yet.
Underlayer is headless, API-first training for SaaS products. Instead of sending your users to a separate LMS portal, you generate a course, embed it where they already work, and get every completion sent back to your own systems. How it works Create a course. Generate one from a doc or a prompt...
What each product offers, as listed by its team.


Possible disadvantages
No features have been listed yet.
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
No analysis of Underlayer yet.
Walkthroughs and reviews on video.
Alex Vieira on Unbiased GitBook Review Perfect for Everyone
More videos
Underlayer demo
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing GitBook and Underlayer.
Underlayer's answer:
it's pre-launching
Underlayer's answer:
Underlayer is training with no portal. You build a course by API, by MCP, or in the visual builder, and add it to your product with one iframe. Then signed webhooks tell your systems who finished. Learners never create an account or leave your app, and the player uses your theme, so it looks like part of your product. We charge per course view, not per seat, and every price and overage rate is published.
Underlayer's answer:
Most course tools, like Coassemble, Trainn and LearningStudioAI, assume training happens on their own site: learners sign up, log in and get enrolled, and you pay per seat. Underlayer takes the opposite approach:
No learner accounts. You pass in your own user IDs and we track progress against them. Built for developers. A full REST API covers every resource, and an MCP server lets AI agents create and edit courses. Results in your own tools. Signed webhooks send completions to your CRM, your product or your data warehouse. SCORM 1.2 and 2004 export for customers who still need to load courses into an LMS. Public pricing. Plans start at $149/month for 25,000 course views, with unlimited learners and no sales call required.
Underlayer's answer:
SaaS product, customer success and engineering teams who want onboarding, product education or compliance training inside their own app. It also suits platforms that train other people's users, like partner networks, marketplaces and field-ops tools, where a separate LMS login gets in the way.
Underlayer's answer:
Every company putting training in front of its users hit the same wall: the LMS wanted to own the learner. That meant a separate portal, a second login and a per-seat bill for people who never opened a course. We built Underlayer as the layer underneath instead. You keep the product and the user relationship. We handle building the course, playing it and tracking progress, and we stay out of the way.
Underlayer's answer:
Next.js 16 (App Router) with React 19 and TypeScript, Tailwind CSS v4, and Supabase (Postgres with row-level security, Auth and Storage). Claude from Anthropic generates courses with AI. Stripe handles billing and Resend sends email. There is also a remote MCP server with OAuth 2.1 for AI-agent access.
Share your experience with using GitBook and Underlayer. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


GitBook can be a good option for internal knowledge bases, as it offers features such as collaboration, version control, and easy customization. However, the suitability of GitBook for your specific use case depends...
It is a standard paperwork system where all products, APIs, and internal understanding bases can be tape-recorded by teams. It’s a platform for users to believe and track concepts. Gitbook is a tool in an innovation...
Their doc editor is simple and powerful, allowing you to use Markdown, and code snippets, as well as embed content. Since GitBook doesn’t have a built-in code editor, you’ll have to use the integration with GitHub for...
We have no reviews of Underlayer yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


GitBook is simple and clean, and sometimes that’s exactly what you need. I like it for early-stage products or teams with lighter documentation. You’ll eventually hit limits if your structure gets more complex, but if simplicity is your... - Source: dev.to / 11 months ago
TL,DR: LaunchDarkly is great for B2C companies. Bucket is for B2B SaaS products, like GitBook — a modern, AI-integrated documentation platform. - Source: dev.to / over 1 year ago
Addison Schultz, Developer Relations Lead at GitBook, puts it simply:. - Source: dev.to / over 1 year ago
Tracking Underlayer since Sep 2026.
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Easy to maintain open source documentation websites
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Trainn is a Customer Education platform for SaaS companies of all sizes to onboard and train customers, at scale, using product training & how-to videos, feature walkthroughs, and a dedicated customer training Academy.
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Archbee is a developer-focused product docs tool for your team. Build beautiful product documentation sites or internal wikis/knowledge bases to get your team and product knowledge in one place.
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