Features
- Resumability — no hydration needed
- Lazy-loads JavaScript at interaction granularity
- Near-zero JS sent on initial page load
- JSX-based component model
- Built-in optimizer for automatic code splitting
Pros
- Best possible Time-to-Interactive for any app size
- Scales without degrading startup performance
- Familiar JSX syntax for React developers
Cons
- Young ecosystem with fewer libraries
- Serialization constraints require learning new patterns
- Smaller community and limited hiring pool
Overview
Qwik is a web framework that introduces a fundamentally new approach to JavaScript delivery called resumability. Traditional frameworks hydrate on the client — they re-execute all component code to rebuild the application state and attach event listeners. Qwik skips this entirely by serializing the application state and framework metadata into HTML, then lazy-loading only the JavaScript needed when a user actually interacts.
This means a Qwik application sends near-zero JavaScript on initial page load regardless of application complexity. Code is downloaded and executed on demand at the granularity of individual interactions, making startup performance constant rather than proportional to application size.
When to Use
Qwik is the right choice when initial load performance is your top priority, particularly for content-heavy sites, e-commerce, or any application where Time-to-Interactive directly impacts business metrics. It’s especially compelling for large applications where traditional hydration costs would be prohibitive.
Getting Started
npm create qwik@latest
cd my-app && npm install && npm startimport { component$, useSignal } from "@builder.io/qwik";
export const Counter = component$(() => {
const count = useSignal(0);
return <button onClick$={() => count.value++}>Count: {count.value}</button>;
});