Inferno 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 fast, React-like JavaScript library for building user interfaces in the browser and on servers.
Open source · MIT
A small (about 4kB) React-style library for building user interfaces in JavaScript.
The short answer
Choose Inferno if you need…
- Developers already familiar with React who want a React-like API
- Projects that re-render frequently with real-time data or large DOM trees
- Teams that want server-side rendering through inferno-server
- Developers who want to use JSX compiled by Babel, SWC or TypeScript plugins
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
| Inferno | Preact | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 16.5k | 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 | 6 days ago | 4 days ago |
What each one is
Inferno
Inferno is a JavaScript library for building user interfaces, with an API modeled on React, so many React concepts such as components, props and state carry over. Its stated focus is runtime rendering speed, especially for views that update often with real-time data or render large DOM trees. It can render on the client and on the server using inferno-server.
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
Inferno
- Developers already familiar with React who want a React-like API
- Projects that re-render frequently with real-time data or large DOM trees
- Teams that want server-side rendering through inferno-server
- Developers who want to use JSX compiled by Babel, SWC or TypeScript plugins
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
Inferno
- The README describes compile-time JSX optimizations and child flags that can reduce runtime work
- Familiar React-like API and component model
- Works without polyfills on tested browsers, per the README's browser support section
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
Inferno
- Teams that depend on the React ecosystem of libraries and tooling, since Inferno is a separate library with its own plugins and compatibility details
- Beginners looking for a large body of tutorials, because the README does not point to a learning path beyond docs and examples
- Projects on very old runtimes, since the README lists features v9 requires at runtime (Promise, Array.prototype.includes and others) and recommends checking compatibility for your targets
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
Inferno
- Version 10 requires matching v10 versions of the Babel, SWC or TypeScript plugins, and JSX compiled by older plugins will not work
- Some performance optimizations, such as child flags, depend on developers following contracts the README warns can crash the app if broken
- Some React-style features differ, so existing React code may need changes
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
Inferno
Clone the repository
git clone https://github.com/infernojs/infernoFrequently asked questions
What is the difference between Inferno and Preact?
Inferno: A fast, React-like JavaScript library for building user interfaces in the browser and on servers. Preact: A small (about 4kB) React-style library for building user interfaces in JavaScript. Inferno suits developers already familiar with react who want a react-like api, while Preact suits web developers who already know react and want a lighter library.
Are Inferno and Preact free?
Inferno: Free and open source. Preact: Free and open source.
Is Inferno or Preact more popular?
Preact has more GitHub stars (39k) than Inferno (16.5k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Inferno and Preact?
Other options people compare them with include React, Svelte, Solid, MDX, react-virtualized.
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.