Free Documentation and API Reference Tools
Which documentation and API reference tools a startup can publish its product and developer docs with for free today, whether the free plan includes a custom domain, how many editors and pages it covers, whether a card is needed and what the first paid plan costs, read from each provider's own page.
Free allowances read on each provider's own pages, all checked on or after . Documentation tools change their free plans from time to time: confirm the terms on the provider's page before you rely on it.
Documentation tools a startup can publish docs with for free today include Mintlify (Starter plan free forever), Docusaurus (Free for everyone), ReadMe (Starter plan free for everyone), Starlight (Free docs theme for Astro), and Fern (Free forever, 1,000 pages). Each of the 13 free plans below links to the provider's page that states it, with its main limit, whether a custom domain is included, whether a card is needed and what the first paid plan costs.
Product docs and an API reference are often the first thing a developer reads before trying your product. Hosted documentation platforms publish them with search and an API playground, several with a free plan, and open-source frameworks build a docs site from Markdown for free.
The headline rarely tells you how far it goes. Free plans cap editors, projects or pages, keep custom domains or analytics for paid plans, or are free only for open-source projects. Each tool below shows what is free, its main limit, whether a custom domain is included, whether a card is needed and what the first paid plan costs, quoted from the provider's own page with the date we read it.
Which tools we picked and the order they appear in are our editorial choices; the terms are the providers'. Some of these providers pay us a referral commission when someone signs up through our link: those links are labeled, and they play no part in which tools are listed or where.
Documentation platforms with a free plan
Publish product and API docs on a hosted platform, free to start.
- 1
Mintlify
Teams that want a hosted docs site on their own domain
The Starter plan is free forever and includes a custom domain, with up to 5 editor seats. Pro is $450/month billed annually.
- Custom domain
- Custom domain included (source: mintlify.com)
- Payment card
- No credit card required (source: mintlify.com)
- First paid plan
- Pro: $450/month billed annually (source: mintlify.com)
Start free at MintlifyTerms read on mintlify.com on Mintlify: the free allowance and how to start Mintlify for Startups: what startups get - 2
ReadMe
Small teams wanting an interactive API reference, free
The Starter plan is free for everyone, with one project and a custom domain. Pro is $250 a month, billed annually.
- Custom domain
- Custom domain on Starter (source: readme.com)
- First paid plan
- Pro: $250/month billed annually (source: readme.com)
- 3
Fern
API teams that want docs and an API explorer, free
The Free plan is free forever, with up to 10 team members and a custom domain and subpath. Enterprise pricing is tailored to each team.
- First paid plan
- Enterprise: custom pricing (source: buildwithfern.com)
- 4
Scalar
Small API teams with up to 3 APIs
Free covers up to 3 APIs and 1 editor seat, with no card needed. After the trial, publishing a Docs site needs a paid plan.
- Custom domain
- No custom domain on Free (source: scalar.com)
- Payment card
- No credit card required (source: scalar.com)
- First paid plan
- Pro: $150/mo, $125 billed yearly (source: scalar.com)
- 5
Theneo
Small teams with a few projects and a developer portal
The Starter Package is free, with up to 2 private projects. Business is $120 per month per workspace, billed annually.
- What's free
- Free Starter Package (source: theneo.io)
- First paid plan
- Business: $120/mo, billed annually (source: theneo.io)
- 6
Archbee
Open-source projects that want a knowledge portal
The free Growing plan is for open-source software. It has unlimited readers and a custom domain and branding, and Growing starts at $80 per month.
- Main limit
- Unlimited readers (source: archbee.com)
- Custom domain
- Custom domain and branding (source: archbee.com)
- First paid plan
- Growing: from $80 a month (source: archbee.com)
- 7
Bump.sh
Open-source projects with an OpenAPI or AsyncAPI spec
Open-source projects can submit for free access to the Pro plan, which has 30 API docs and 50 MCP tools. Custom domain and logo are included.
- Custom domain
- Custom domain and logo (source: bump.sh)
- First paid plan
- Basic: $50/month (source: bump.sh)
- 8
Redocly
Open-source projects that lint and render OpenAPI
Redocly CLI is free and open source, and hosted Redocly tools start with a 30-day trial. Pro is $249 a month, billed annually.
- What's free
- Free open-source CLI (source: redocly.com)
- First paid plan
- Pro: $249/month billed annually (source: redocly.com)
Open-source documentation frameworks
Build docs sites from Markdown and host them anywhere, free.
- 1
Docusaurus
React teams that host a versioned docs site themselves
Docusaurus is free for everyone. The site is built into static files that you put on a web server yourself.
- What's free
- Free for everyone (source: docusaurus.io)
Start free at DocusaurusTerms read on docusaurus.io on Docusaurus: the free allowance and how to start - 2
Starlight
Astro users who want a fast docs site
Starlight's theme page lists its cost as free. It is a documentation theme built on top of the Astro framework.
- 3
MkDocs Material
Python and MkDocs users who want a polished docs site
Material for MkDocs is MIT-licensed. Critical maintenance continues through May 5, 2027, while Zensical, its successor, is developed.
Start free at Material for MkDocsTerms read on squidfunk.github.io on MkDocs Material: the free allowance and how to start - 4
Nextra
Teams wanting a free MDX docs framework
The Nextra project and themes are licensed under the MIT license, so both are free to use.
- What's free
- Free, MIT-licensed (source: nextra.site)
- 5
VitePress
Teams wanting a free static docs site generator
VitePress is released under the MIT License, so it is free to use.
- What's free
- Free, MIT-licensed (source: vitepress.dev)
Start free at VitePressTerms read on vitepress.dev on VitePress: the free allowance and how to start
Developer startup programs
Programs from developer tool companies that give startups credits or discounts on paid plans.
Also useful for team productivity
Referral links, picked for fit and ordered by fit (70%) and what a signup earns us (30%), at no cost to you. They never change this page's ranking.
Compare the top options
How this comparison is built
The list covers documentation and API reference tools a founder can use for free today without applying to a program. The order and the "best for" notes are our editorial reading of each tool's terms. Every term comes from the tool's own pricing or help page on the date shown, never from a third-party list; follow each link for the full conditions. A custom domain or analytics kept for paid plans, a cap on editors or pages, the vendor's branding on free docs can matter more than the headline, so the comparison quotes them wherever the provider states them. Some of these tools pay StartupPerks a referral commission, and their links are labeled as referral links; that decides neither whether nor where a tool appears, and no tool pays for a placement on this page.
Read the full methodologyCommon questions
What is the best free documentation tool?
It depends on your team. By the terms each provider states, Mintlify's Starter plan is free forever with up to 5 editor seats and a custom domain, Fern is free forever for 1,000 pages, ReadMe's Starter plan is free with 1 project, and Docusaurus is free for everyone to self-host.
Is Mintlify free?
Mintlify's Starter plan is free forever with up to 5 editor seats and a custom domain; its Pro plan is $450 a month, billed annually.
Is there a free open-source documentation framework?
Yes. Docusaurus, Nextra, VitePress and MkDocs Material are free and open source, and Starlight is a free docs theme for Astro.
Which docs tools are free for open-source projects?
By their own pages, Archbee offers its Growing plan free for open source, and Bump.sh its Pro plan.
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