MDX vs Preact
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A format for writing Markdown documents that can embed live JSX components.
Open source · MIT
A small (about 4kB) React-style library for building user interfaces in JavaScript.
The short answer
Choose MDX if you need…
- Developers building documentation or content sites in React, Preact, or Vue
- Teams that want interactive components inside long-form written content
- Projects that already use webpack, Rollup, or similar bundlers
- People who are comfortable with JavaScript and JSX syntax
Choose Preact if you need…
- Web developers who already know React and want a lighter library
- Projects where small bundle size matters, such as pages loaded over slow connections
- Teams that want an optional compatibility alias (preact/compat) to reuse React-based code
- Developers building apps that need server-side rendering with hydration
Side-by-side
| MDX | Preact | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 19.8k | 39k |
| Setup difficulty | Intermediate | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | JavaScript | JavaScript |
| Last code update | 7 days ago | 4 days ago |
What each one is
MDX
MDX is a file format that lets you write JSX components inside Markdown documents, such as importing an interactive chart or alert and placing it within your text. The repository contains several packages that compile MDX into JavaScript, integrate with bundlers like webpack and Rollup, and work with frameworks such as React, Preact, and Vue. It is used for long-form content that needs components.
Preact
Preact is a JavaScript library for building user interfaces out of reusable components, using an API that closely follows React. The README describes it as a fast, roughly 4kB alternative to React with a similar modern API, covering components, hooks, JSX, and a virtual DOM. Developers use it when they want React-style code with a much smaller download size.
Best for
MDX
- Developers building documentation or content sites in React, Preact, or Vue
- Teams that want interactive components inside long-form written content
- Projects that already use webpack, Rollup, or similar bundlers
- People who are comfortable with JavaScript and JSX syntax
Preact
- Web developers who already know React and want a lighter library
- Projects where small bundle size matters, such as pages loaded over slow connections
- Teams that want an optional compatibility alias (preact/compat) to reuse React-based code
- Developers building apps that need server-side rendering with hydration
Strengths
MDX
- Lets you combine Markdown writing with reusable components
- Works with several bundlers and frameworks according to the README
- Open source under the MIT license with an active project and public documentation
Preact
- Very small size (the README states about 4kB), which helps page load time
- Familiar React API, including class components, hooks, and functional components
- MIT licensed with a large community and many stars on GitHub
Not ideal for
MDX
- Writers who only need plain Markdown, since MDX adds JSX syntax that plain Markdown renderers will not understand
- Non-developers without JavaScript experience, because setup requires build tooling
- Projects not using a JavaScript-based framework, as the README focuses on React, Preact, and Vue
Preact
- Complete beginners who have never written JavaScript; the README assumes familiarity with components and modern JS syntax
- Projects that depend on React-only libraries without testing compatibility, since the README only describes compatibility as 'extensive' via an alias and does not list limits
- Native mobile app development, which the README does not mention
Trade-offs
MDX
- Requires JavaScript build tooling to use in a project
- Content mixing JSX and Markdown can be harder to read and maintain than plain Markdown
- The README is brief on specifics, so details must be found in the linked documentation
Preact
- The README is truncated and gives limited detail on edge-case React compatibility
- Some React ecosystem libraries may need the compat layer or may not work fully
- Tooling such as DevTools and HMR depends on additional setup that the README only briefly mentions
Getting started
Frequently asked questions
What is the difference between MDX and Preact?
MDX: A format for writing Markdown documents that can embed live JSX components. Preact: A small (about 4kB) React-style library for building user interfaces in JavaScript. MDX suits developers building documentation or content sites in react, preact, or vue, while Preact suits web developers who already know react and want a lighter library.
Are MDX and Preact free?
MDX: Free and open source. Preact: Free and open source.
Is MDX or Preact more popular?
Preact has more GitHub stars (39k) than MDX (19.8k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to MDX and Preact?
Other options people compare them with include react-markdown, Vditor, Inferno, Tiptap, AutoAnimate.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.