18.4
Scalar is a collection of API products for documentation, client generation, API management, requests, and MCP server use.
Free planOpen sourceWebAPILinux
Best API Docs in 2026
API documentation tools help you turn API definitions or source code into readable reference pages, examples and interactive guides. Depending on the product, you may publish on the web, run a self-hosted setup, or use command-line tools on Linux, macOS or Windows. Compare the free plan and starting paid price, then check OpenAPI import, custom domains, docs-as-code workflows, an interactive API explorer, versioning…
28.0
Mintlify is a documentation and knowledge platform for developers and AI agents.
Free planWebAPILinux
37.9
doccano is a free, open-source tool for labeling text and other data for human review and machine-learning work.
Free planOpen sourceAndroidiOSWeb
- 4
Fern
Fern Docs builds interactive documentation websites from Markdown and API specifications, while Fern also generates strongly typed client libraries.
Free planOpen sourceWebAPILinuxmacOS7.8Free plan - 5
Theneo
Theneo is a developer portal platform for publishing API references, guides, changelogs, and private customer portals.
Free planWebAPIExtensionSelf-hosted7.5From $120 a month - 6
APIMatic
APIMatic turns API contracts into SDKs, documentation, developer portals, code samples, Context Plugins, and MCP servers.
Free planWebAPIExtensionLinux7.4From $99 a month - 7
SwaggerHub
SwaggerHub is a toolkit for API design, testing, documentation, and governance.
Free planWebSelf-hosted7.1From $740 a year - 8
Redocly
WebAPIExtension7.0From $10 a month - 9
ReadMe
Free planWeb6.7From $250 a month - 10
TypeDoc
TypeDoc is a free documentation generator for TypeScript projects.
Free planAPILinuxSelf-hosted6.5Free plan - 11
Bump.sh
Bump.sh is a paid web, API, and self-hosted service for publishing API documentation and providing MCP servers that update with API releases.
WebAPISelf-hosted6.4From $50 a month - 12
Stoplight Elements
Free planWebSelf-hosted6.4Free plan - 13
Zudoku
Zudoku is a free, open-source framework for building API documentation and developer portals around OpenAPI.
Free planWebSelf-hosted6.1Free plan - 14
Jazzy
Jazzy is a free, MIT-licensed command-line utility for generating Swift and Objective-C documentation.
Free planLinuxmacOS6.0Free plan - 15
Widdershins
Widdershins converts API definition files into documentation inputs for rendering pipelines.
Free planAPILinuxSelf-hosted6.0Free plan - 16
AsyncAPI Generator
AsyncAPI Generator is free, open-source software that uses an AsyncAPI document and a template to create documentation, code, diagrams,…
Free planLinuxSelf-hosted5.9Free plan - 17
RAML2HTML
RAML2HTML is a free, open-source Node.js package that generates HTML documentation from RAML.
Free planLinuxSelf-hosted5.8Free plan - 18
JSDoc
APISelf-hosted5.4 - 194.4
Choosing well
Check where you can work
The listed platforms include self-hosted, web, API, Linux, macOS and Windows.
A self-hosted option can suit teams that want to run the service themselves, while a web tool may fit browser-based publishing.
Compare free and paid access
A free plan is offered by items in this category, and open-source projects are available as well. Paid starting points differ, so compare the listed price with your documentation needs.
Some paid services include a free trial, while freemium tools combine a free plan with paid features. Check the plan terms before moving a live project.
Match your documentation workflow
Look for OpenAPI import if your API descriptions already use that format. Docs-as-code support can matter when documentation belongs in a code repository and follows development changes.
Source-focused tools may accept inputs such as Kotlin with KDoc, Java with Javadoc, Markdown, or JavaScript comments. Choose inputs that match your project.
Plan the reader experience
An interactive API explorer can let readers work with endpoints from the documentation. Documentation versioning helps present different API releases, while analytics can show how readers use the docs.
If you publish under your own address, check for custom-domain support and confirm which plan includes it.
Questions people ask
Can I start without paying?
Yes. Items in this category offer free plans, and open-source options are available. Terms and included features vary by tool.
Which tools are open source?
The list includes open-source projects such as AsyncAPI Generator, doccano, Dokka, Jazzy and RAML2HTML.
Are free trials available?
Some paid services offer trials. APIMatic and Bump.sh list 14-day trials in their pricing notes.
Can these tools import OpenAPI files?
OpenAPI import is one of the comparison points for this category. Check the individual tool's feature details before choosing.