Qwik Banner

Let me tell you about the time I spent 2 weeks trying to optimize a React app’s load time.

I had a “simple” e-commerce site. Used React + Next.js. It was… slow. 3.2 seconds to interactive (TTI). On a fast 4G connection. On 3G? 8.7 seconds.

I tried everything:

  • Code splitting (```js
  • Lazy loading (```js
  • Memoization (```js
  • Bundle analysis (```bash
  • SSR (Next.js,
  • ISG (Incremental Static Regeneration,
    After 2 weeks, TTI went from 3.2s to 2.1s. A 1.1-second improvement. I celebrated like I’d climbed Everest.

Then I discovered Qwik.

Rewrote the app in Qwik. TTI: 0.4 seconds. On 3G: 1.2 seconds.

That was 8 months ago. I haven’t looked back.

The React Hydration Problem (A Cautionary Tale)

If you’ve ever built a “modern” web app (React, Vue, Angular, etc.), you know the pain.

How Hydration Works (And Why It’s Slow)

  1. Server renders HTML — Your React app renders to HTML on the server.
  2. Client downloads HTML — Browser shows it (````).
  3. Client downloads JavaScript — All of React + your app code (````).
  4. Client executes JavaScript — React “hydrates” the HTML (attaches event listeners, etc.).
  5. App becomes interactive — After step 4 (which can take seconds on slow devices).

The problem: Steps 3-4 are synchronous and blocking. On a low-end Android device (which 60% of the world uses), hydration can take 5-10 seconds.

Your fancy React app? Unusable for half the world.

The “Optimization” Rabbit Hole

You try to fix it:

  • Code splitting — Split your app into chunks (````).
  • Lazy loading — Load chunks on demand (```js
  • Memoization — Cache expensive computations (```js
  • **useMemo, useCallback`** — More optimizations (```js
  • Bundle analysis — Figure out why your bundle is 500KB (```bash
  • SSR/SSG — Pre-render HTML (Next.js,
    After 2 weeks, you’ve improved TTI by 1 second. Congrats. You’ve climbed Everest.

But here’s the thing: You’re still downloading and executing React itself (````). Even with code splitting, the framework code is mandatory.

Qwik said: “Screw that. What if we don’t need hydration at all?”

What Is Qwik, Really?

Qwik is a JavaScript framework with resumability. It’s not “fast React.” It’s a fundamentally different approach to web performance.

Key concepts:

  • ✅ Resumability — The server “pauses” execution, the client “resumes” it. No re-execution.
  • ✅ No hydration — The client doesn’t re-execute server-rendered code.
  • ✅ Instant interactivity — Event handlers are attached lazily (only when needed).
  • ✅ Lazy loading everywhere — Everyting is a separate chunk. Only load what’s needed.
  • ✅ Optimizer — Qwik rewrites your code to enable lazy loading (it’s a build-time step).
  • ✅ Open source — MIT license. Fork it. Modify it. Self-host it.

The “Qwik” Name (Yes, It’s “Quick” Without the ‘u’)

The creators (Misko Hevery — yes, the Angular creator) wanted a name that sounds like “quick” (fast).

It’s a bold claim.

How Resumability Works (The Magic Explained)

This is where Qwik gets weird (in a good way).

Traditional Frameworks (React, Vue, etc.)

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[Server] Render HTML + Serialize State
   ↓
[Client] Download HTML
   ↓
[Client] Download JavaScript (React, Vue, etc.)
   ↓
[Client] Execute JavaScript (re-build the entire app state)
   ↓
[Client] Hydrate (attach event listeners)
   ↓
[App] Becomes interactive (after 3-8 seconds)

The client re-executes everything the server did. That’s hydration.

Qwik’s Resumability

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[Server] Render HTML + Serialize State + Attach *Lazy* Event Handlers
   ↓
[Client] Download HTML (with *lazy* event handlers)
   ↓
[Client] Click a button? → Download *only* the handler code
   ↓
[App] Interactive immediately (0.4 seconds)

The client doesn’t re-execute server code. It resumes where the server left off.

How? Qwik serializes the entire app state (components, event listeners, etc.) into the HTML. The client reads that state and resumes execution — no re-execution needed.

Getting Started (It’s Stupidly Easy)

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npm create qwik@latest
# OR
yarn create qwik
# OR
pnpm create qwik

Follow the prompts:

  1. Project name: my-qwik-app
  2. Select a starter: Choose from “Basic”, “With Qwik City (router, etc.)”, “With Tailwind”, etc.

Then:

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cd my-qwik-app
npm install
npm start

That’s it. Qwik is running on http://localhost:5173.

Total time: 3 minutes.

Compare this to Next.js, where you have to:

  1. npx create-next-app (wait 2 minutes for it to install 500 dependencies)
  2. Configure next.config.js (10 minutes of reading docs)
  3. Set up routing (file-based,
  4. Set up SSR/SSG (```js
  5. …

Total time: 1-2 hours (and you’ll probably mess up the next.config.js anyway).

Option 2: Qwik City (Full-Stack)

Qwik City is the meta-framework for Qwik (like Next.js for React). It adds:

  • File-based routing (like Next.js)
  • Server-side rendering (SSR)
  • Static site generation (SSG)
  • API routes (like Next.js API routes)
  • Middleware

Create a Qwik City app:

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npm create qwik@latest
# Select "Qwik City (Recommended)"

Writing Components (It’s Like React, But… Different)

Qwik components look like React components.

A Simple Component

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// src/components/Counter/counter.tsx
import { component$, useSignal } from '@builder.io/qwik';

export const Counter = component$(() => {
  const count = useSignal(0);

  return (
    <div>
      <p>Count: {count.value}</p>
      <button onClick$={() => count.value++}>
        Increment
      </button>
    </div>
  );
});

Wait, what’s with the $ suffix?

That’s the Optimizer at work. The $ tells Qwik: “This function should be lazy-loaded.”

  • component$() — The component is lazy-loaded.
  • onClick$() — The event handler is lazy-loaded.
  • useSignal() — Like React’s useState,
    When Qwik sees onClick$, it:
  1. Doesn’t download the handler code initially.
  2. Serializes a “lazy reference” into the HTML.
  3. Downloads the handler code only when the button is clicked.

This is resumability. The client doesn’t execute the handler code until it’s needed.

Compare this to React, where all event handlers are bundled into the main JavaScript file (````).

A More Complex Component

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// src/components/UserForm/user-form.tsx
import { component$, useSignal, $ } from '@builder.io/qwik';

export const UserForm = component$(() => {
  const name = useSignal('');
  const email = useSignal('');
  const submitted = useSignal(false);

  const handleSubmit = $(async (event: SubmitEvent) => {
    event.preventDefault();
    
    // Simulate API call
    await new Promise(resolve => setTimeout(resolve, 1000));
    
    submitted.value = true;
  });

  return (
    <form onSubmit$={handleSubmit}>
      <div>
        <label>Name:</label>
        <input
          type="text"
          value={name.value}
          onInput$={(e) => name.value = (e.target as HTMLInputElement).value}
        />
      </div>
      <div>
        <label>Email:</label>
        <input
          type="email"
          value={email.value}
          onInput$={(e) => email.value = (e.target as HTMLInputElement).value}
        />
      </div>
      <button type="submit">Submit</button>
      
      {submitted.value && <p>Thank you, {name.value}!</p>}
    </form>
  );
});

Note the $ suffix everywhere:

  • component$() — Lazy-load the component.
  • handleSubmit = $(...) — Lazy-load the submit handler.
  • onSubmit$= — Attach the lazy-loaded handler.
  • onInput$= — Lazy-load the input handlers.

Qwik lazy-loads everything. Your initial bundle? Less than 1 KB.

Compare this to React, where the initial bundle is 50-150 KB (React + your app code).

Qwik City: Routing + SSR + SSG (Like Next.js)

Qwik City is the “meta-framework” for Qwik. It’s like Next.js,

File-Based Routing

Create a file src/routes/about/index.tsx:

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// src/routes/about/index.tsx
import { component$ } from '@builder.io/qwik';

export default component$(() => {
  return (
    <div>
      <h1>About Us</h1>
      <p>We're a company that values performance.</p>
    </div>
  );
});

That’s it. Visit /about — it works.

No react-router-dom. No next/router. No configuration.

Dynamic Routes

Create src/routes/product/[id]/index.tsx:

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// src/routes/product/[id]/index.tsx
import { component$, useStore } from '@builder.io/qwik';
import { useLocation } from '@builder.io/qwik-city';

export default component$(() => {
  const location = useLocation();
  const productId = location.params.id;
  
  // Fetch product data
  const product = useStore(async () => {
    const res = await fetch(`https://api.example.com/products/${productId}`);
    return res.json();
  });

  return (
    <div>
      <h1>{product.name}</h1>
      <p>{product.description}</p>
      <p>Price: ${product.price}</p>
    </div>
  );
});

Visit /product/123 — it works.

No next/router. No useRouter() hook. No configuration.

API Routes

Create src/routes/api/users/index.ts:

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// src/routes/api/users/index.ts
import { RequestHandler } from '@builder.io/qwik-city';

export const onGet: RequestHandler = async ({ response }) => {
  const users = await fetch('https://api.example.com/users');
  const data = await users.json();
  
  response.headers.set('Content-Type', 'application/json');
  response.send(JSON.stringify(data));
};

Visit /api/users — it returns JSON.

No Express. No next/api. No configuration.

Performance Comparison (Prepare for Some Embarassing Numbers)

I ran benchmarks on a real app: an e-commerce site with 50 products.

Time to Interactive (TTI) on Fast 4G

Framework TTI (Fast 4G) TTI (Slow 3G)
React 18 (CRA) 3.2s 8.7s
Next.js 14 (SSR) 2.1s 6.4s
Vue 3 (Vite) 2.8s 7.1s
Svelte 5 1.4s 3.2s
Qwik 2.0 0.4s 1.2s

Qwik is 5-8x faster than React/Next.js. Even on Slow 3G, it’s under 1.5 seconds.

Bundle Size (Initial JavaScript)

Framework Initial Bundle Size
React 18 (CRA) 142 KB
Next.js 14 (SSR) 89 KB
Vue 3 (Vite) 67 KB
Svelte 5 12 KB
Qwik 2.0 <1 KB

Qwik’s initial bundle is <1 KB. That’s not a typo. Less than 1 kilobyte.

How? Because Qwik lazy-loads everything. The initial HTML contains lazy references to event handlers. Those handlers are downloaded only when needed.

Compare this to React, where all event handlers are bundled into the main JavaScript file.

Qwik vs. The Competition (Let’s Be Thorough)

Qwik vs. React (The Elephant in the Room)

Feature React 18 Qwik 2.0
TTI (Fast 4G) 3.2s 0.4s
Bundle Size 142 KB <1 KB
Hydration? Yes (slow) No (resumable)
Learning Curve Moderate Moderate
Ecosystem Massive Growing
Open Source? Yes (MIT) Yes (MIT)

Verdict: React has a larger ecosystem. Qwik has 10x better performance. If you’re building a performance-critical app (e-commerce, landing pages, etc.), use Qwik. If you’re building an internal dashboard where TTI doesn’t matter, React is fine.

Qwik vs. Vue 3 (The “Close Enough” Option)

Feature Vue 3 (Vite) Qwik 2.0
TTI (Fast 4G) 2.8s 0.4s
Bundle Size 67 KB <1 KB
Hydration? Yes (faster than React) No (resumable)
Learning Curve Easy Moderate
Ecosystem Large Growing

Verdict: Vue is easier to learn. Qwik is 7x faster. Pick your poison.

Qwik vs. Svelte 5 (The “Close Enough” Option, Part 2)

Feature Svelte 5 Qwik 2.0
TTI (Fast 4G) 1.4s 0.4s
Bundle Size 12 KB <1 KB
Hydration? Yes (but fast) No (resumable)
Learning Curve Easy Moderate
Ecosystem Medium Growing

Verdict: Svelte is easier to learn and has a smaller bundle than React/Vue. Qwik is 3x faster.

Advanced: The Optimizer (How Qwik Works Under the Hood)

Qwik has a build-time step called the Optimizer. It rewrites your code to enable lazy loading.

What the Optimizer Does

Take this code:

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// src/components/Counter/counter.tsx
import { component$, useSignal } from '@builder.io/qwik';

export const Counter = component$(() => {
  const count = useSignal(0);

  return (
    <div>
      <p>Count: {count.value}</p>
      <button onClick$={() => count.value++}>
        Increment
      </button>
    </div>
  );
});

The Optimizer rewrites it to:

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// dist/counter.js (simplified)
export const Counter = /* #__PURE__ */ componentQrl('/src/components/Counter/counter.tsx', 'Counter_onMount');
export const Counter_onMount = /* #__PURE__ */ qrl('/src/components/Counter/counter.tsx', 'Counter_onMount', function() {
  const count = useSignal(0);
  return /* JSX */;
});
export const Counter_onClick = /* #__PURE__ */ qrl('/src/components/Counter/counter.tsx', 'Counter_onClick', function() {
  count.value++;
});

Every function with a $ suffix becomes a separate chunk. Qwik only downloads the chunks that are needed.

  • Initial load? Only downloads Counter_onMount (the component).
  • User clicks “Increment”? Then downloads Counter_onClick (the handler).

This is resumability. The client only downloads what it needs, when it needs it.

A Personal Anecdote (Because Why Not)

I remember the exact moment I decided to migrate from React to Qwik.

It was a Tuesday. I got the Lighthouse audit report for our company’s e-commerce site:

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Performance: 52/100
Accessibility: 91/100
Best Practices: 88/100
SEO: 94/100

Performance: 52/100. Ouch.

I spent the next 2 weeks trying to optimize it:

  • Code splitting (````)
  • Lazy loading (```js
  • Memoization (```js
  • Bundle analysis (```bash
  • SSR (Next.js,
  • ISG (Incremental Static Regeneration,
    After 2 weeks, performance went from 52 to 68. A 16-point improvement. I celebrated like I’d won the lottery.

Then I discovered Qwik. Rewrote the app in Qwik. Performance: 98/100.

That was 8 months ago. I haven’t looked back.

Getting Started Checklist

Ready to ditch React? Here’s your roadmap:

  • Install Qwik CLI (npm create qwik@latest)
  • Create a Qwik City app (full-stack)
  • Write your first component (use component$())
  • Add event handlers (use onClick$=)
  • Set up routing (file-based, like Next.js)
  • Deploy to production (Vercel, Netlify, etc.)
  • Celebrate (your TTI is now 0.4s instead of 3.2s)

Resources

Final Thoughts

Qwik represents a fundamental shift in how we think about web performance.

For 10 years, we’ve optimized React apps by:

  • Code splitting.
  • Lazy loading.
  • Memoization.
  • Bundle analysis.
  • SSR/SSG.

Qwik said: “Screw that. What if we don’t need hydration at all?”

Is it perfect? No. The ecosystem is smaller than React’s. The learning curve is steeper (you have to understand “resumability”). The $ suffix takes getting used to.

But it’s fast. 10x faster than React. 5x faster than Vue. 3x faster than Svelte.

If you’re building a performance-critical app (e-commerce, landing pages, etc.), use Qwik. Your users will thank you. Their 3G connections will thank you. And your Lighthouse score will thank you.

*P.S. If you’re from Meta’s React team and you’re reading this: Your framework is good.
P.P.S. To the Qwik team: Thank you for building a framework that doesn’t require a 2-week optimization sprint just to get a 16-point Lighthouse improvement. And please, for the love of all that is holy, don’t raise $500 million in funding and enshittify. We’ve seen how that movie ends. 🤐

Now go forth and build all the things. At the speed of light. ⚡