Paul is a Senior Software Engineer, Independent Developer Advocate and Technical Writer. More from Paul can be found on his site, paulie.dev. 
    
 
   
     Read more from Paul Scanlon 
     
   
 
  Before we get going, a disclaimer: I love React but sometimes, I really don’t need it.
Many of my recent projects have been built using Astro (which by default ships zero JavaScript to the client — superb for fast, lightweight and performant content websites). But on occasion, I have needed a little bit of client-side JavaScript to enable interactivity. At this point, I’ve found myself struggling to decide between regular Vanilla JavaScript or React.
On one hand, Vanilla JavaScript is generally more lightweight than React, but it can become difficult to maintain. React somewhat solves this problem, but for minimal client-side JavaScript requirements, it is a bit of a beast.
For these reasons (and a number of others) I started to investigate alternatives to React. And lo and behold, I discovered Qwik.
The official product marketing message is as follows: “Qwik is a new kind of web framework that can deliver instant loading web applications at any size or complexity.”
For me, however, I like to think of Qwik like this: Write code like React, Browser tastes of Vanilla.
Qwik is fundamentally different from React and has been designed from the ground up to facilitate the growing demand for frameworks to work on both the client and the server.
Qwik is lighter than React and less verbose than Vanilla, and doesn’t need any additional 'use client', or client:load directives. It’s smart enough to execute (where necessary) on the server, and resume on the client. The Qwik team has done a much better job of explaining it than I ever could so head over to the docs to find out more: Think Qwik.
As I mentioned, my current exploration into Qwik has mainly been focused around my work with Astro. The excellent @quikdev/astro integration from Jack Shelton has made getting started with Qwik an absolute dream. Here’s a snippet from the docs. As you can see, getting started is as simple as installing the integration and adding it to your Astro config.
 
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        // astro.config.mjs
        
       
        import
         {
         
        defineConfig
         }
         
        from
         
        'astro/config';
        
       
        import 
        qwikdev 
        from
         
        '@qwikdev/astro';
        
       
        export
         
        default
         
        defineConfig({
        
       
          
        integrations:
         [
        qwikdev()],
        
       
        });
        
       |  
    
I can understand the reluctance to switch. Many of my “React friends” have exhibited an unwillingness to make the switch by claiming they know React and don’t want to invest the time in learning something new. That’s a fair point, but how different are the two technologies really?
In the following code snippets, I’ll be covering some common React use cases and showing you how you’d accomplish the same using Qwik. Hopefully, you’ll agree that it’s not an overly steep learning curve.
With all that out of the way, we can now get going!
Here’s a simple React component.
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       |  
     
       
        import 
        React 
        from
         
        'react';
        
       
        const 
        SimpleReactComponent
         =
         ()
         =
        >
         {
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        p
        >
        Hello,
         
        I'
        m
         
        a
         
        simple 
        React 
        component
        </
        p
        >
        
       
            
        </
        div
        >
        
       
          );
        
       
        };
        
       
        export 
        default 
        SimpleReactComponent;
        
       |  
    
 And here’s the Qwik version.
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       |  
     
       
        import
         {
         
        component$
         }
         
        from
         
        '@builder.io/qwik';
        
       
        const 
        SimpleQwikComponent
         =
         
        component$(()
         =
        >
         {
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        p
        >
        Hello,
         
        I'
        m
         
        a
         
        simple 
        Qwik 
        component
        </
        p
        >
        
       
            
        </
        div
        >
        
       
          );
        
       
        });
        
       
        export 
        default 
        SimpleQwikComponent;
        
       |  
    
 The main difference is the use of component$. A full explanation can be found in the Qwik docs here: component$.
In the following example, a button click sets the value of isVisible to either true orfalse.
This boolean value is used to determine if the <span /> containing the Rocket emoji is returned by Jsx. it’s also used to display either the word “Show” or “Hide” in the button.
You can see src code and a preview of this Qwik component on the links below.
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       |  
     
       
        import
         {
         
        useState
         }
         
        from
         
        'react';
        
       
        const 
        UseStateBooleanReactComponent
         =
         ()
         =
        >
         {
        
       
          
        const
         [
        isVisible,
         
        setIsVisible]
         =
         
        useState(
        true);
        
       
          
        const 
        handleVisibility
         =
         ()
         =
        >
         {
        
       
            
        setIsVisible(!
        isVisible);
        
       
          };
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        p
        >
        
       
                
        <
        span
        >
        
       
                  {
        isVisible
         ?
         (
        
       
                    
        <
        span 
        role=
        'img'
         
        aria-label=
        'Rocket'
        >
        
       
                    
        <
        /span>
        
       
                  ) : null}
        
       
                </span
        >
        
       
                
        Hello,
         
        I
        'm a useState boolean React component
        
       
              </p>
        
       
              <button onClick={handleVisibility}>{`${isVisible.value ? '
        Hide
        ' : '
        Show'}
         
        Rocket`}
        </
        button
        >
        
       
            
        </
        div
        >
        
       
          );
        
       
        };
        
       
        export 
        default 
        UseStateBooleanReactComponent;
        
       |  
    
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       |  
     
       
        import
         {
         
        component$,
         
        useSignal,
         $
         }
         
        from
         
        '@builder.io/qwik';
        
       
        const 
        UseSignalQwikComponent
         =
         
        component$(()
         =
        >
         {
        
       
          
        const 
        isVisible
         =
         
        useSignal(
        true);
        
       
          
        const 
        handleVisibility
         =
         $(()
         =
        >
         {
        
       
            
        isVisible
        .
        value
         =
         !
        isVisible
        .
        value;
        
       
          });
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        p
        >
        
       
                
        <
        span
        >
        
       
                  {
        isVisible
        .
        value
         ?
         (
        
       
                    
        <
        span 
        role=
        'img'
         
        aria-label=
        'Rocket'
        >
        
       
                    
        <
        /span>
        
       
                  ) : null}
        
       
                </span
        >
        
       
                
        Hello,
         
        I
        'm a useSignal Qwik component
        
       
              </p>
        
       
              <button onClick$={handleVisibility}>{`${isVisible.value ? '
        Hide
        ' : '
        Show'}
         
        Rocket`}
        </
        button
        >
        
       
            
        </
        div
        >
        
       
          );
        
       
        });
        
       
        export 
        default 
        UseSignalQwikComponent;
        
       |  
    
 The main differences here are with how the handler is defined and how the state, or signal, is declared.
Function declarations are wrapped with $(), which transforms the function into a QRL. You can read more about function handlers in the docs here: Reusing event handlers.
Inside the function is where things get a little more different. With Qwik you update the signal value directly. E.g isVisible.value = true. A signal will only contain the value, and not the setter pair, like React’s useState.
And lastly, watch out for the trailing $ on the onClick attribute. E.g onClick$.
In the following example, the + button adds a Rocket to an array, the – button removes the last item added. Each time the array is modified the page is updated to reflect the change.
You can see src code and a preview of this Qwik component on the links below.
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       |  
     
       
        import
         {
         
        useState
         }
         
        from
         
        'react';
        
       
        const 
        UseStateBooleanReactComponent
         =
         ()
         =
        >
         {
        
       
          
        const
         [
        rockets,
         
        setRockets]
         =
         
        useState([
        '']);
        
       
          
        const 
        handleAdd
         =
         ()
         =
        >
         {
        
       
            
        setRockets((
        prevState)
         =
        >
         [...
        prevState,
         
        '']);
        
       
          };
        
       
          
        const 
        handleRemove
         =
         ()
         =
        >
         {
        
       
            
        setRockets((
        prevState)
         =
        >
         [...
        prevState
        .
        slice(
        0,
         -
        1)]);
        
       
          };
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        div 
        className=
        'h-8'
        >
        
       
                {
        rockets
        .
        map((
        data,
         
        index)
         =
        >
         {
        
       
                  
        return
         (
        
       
                    
        <
        span 
        key={
        index}
         
        role=
        'img'
         
        aria-label=
        'Rocket'
        >
        
       
                      {
        data}
        
       
                    
        </
        span
        >
        
       
                  );
        
       
                })}
        
       
              
        </
        div
        >
        
       
              
        <
        p
        >
        Hello,
         
        I
        'm a useState array React component</p>
        
       
              <div className='
        flex 
        gap-
        4'
        >
        
       
                
        <
        button 
        onClick={
        handleAdd}
        >+
        </
        button
        >
        
       
                
        <
        button 
        onClick={
        handleRemove}
        >-
        </
        button
        >
        
       
              
        </
        div
        >
        
       
            
        </
        div
        >
        
       
          );
        
       
        };
        
       
        export 
        default 
        UseStateBooleanReactComponent;
        
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        import
         {
         
        component$,
         
        useStore,
         $
         }
         
        from
         
        '@builder.io/qwik';
        
       
        const 
        UseStoreQwikComponent
         =
         
        component$(()
         =
        >
         {
        
       
          
        const 
        rockets
         =
         
        useStore([
        '']);
        
       
          
        const 
        handleAdd
         =
         $(()
         =
        >
         {
        
       
            
        rockets
        .
        push(
        '');
        
       
          });
        
       
          
        const 
        handleRemove
         =
         $(()
         =
        >
         {
        
       
            
        rockets
        .
        pop();
        
       
          });
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        div 
        className=
        'h-8'
        >
        
       
                {
        rockets
        .
        map((
        data)
         =
        >
         {
        
       
                  
        return
         (
        
       
                    
        <
        span 
        role=
        'img'
         
        aria-label=
        'Rocket'
        >
        
       
                      {
        data}
        
       
                    
        </
        span
        >
        
       
                  );
        
       
                })}
        
       
              
        </
        div
        >
        
       
              
        <
        p
        >
        Hello,
         
        I
        'm a useStore Qwik component</p>
        
       
              <div className='
        flex 
        gap-
        4'
        >
        
       
                
        <
        button 
        onClick$={
        handleAdd}
        >+
        </
        button
        >
        
       
                
        <
        button 
        onClick$={
        handleRemove}
        >-
        </
        button
        >
        
       
              
        </
        div
        >
        
       
            
        </
        div
        >
        
       
          );
        
       
        });
        
       
        export 
        default 
        UseStoreQwikComponent;
        
       |  
    
 Similar to the useSignal example, the function declarations are wrapped with $() but in my opinion, the way to update the array is more straightforward. A simple/standard JavaScript .push or .pop can be used, rather than the React method of having to spread the previous state before modifying it.
In the context of Astro it might feel odd to even have a client-side data request, but every now and then you probably will need a bit of client-side data fetching — and here’s how you can do that.
You can see src code and a preview of this Qwik component on the links below.
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       |  
     
       
        import
         {
         
        useState,
         
        useEffect
         }
         
        from
         
        'react';
        
       
        const 
        ClientFetchReactComponent
         =
         ()
         =
        >
         {
        
       
          
        const
         [
        data,
         
        setData]
         =
         
        useState(
        null);
        
       
          
        useEffect(()
         =
        >
         {
        
       
            
        const 
        getData
         =
         
        async
         ()
         =
        >
         {
        
       
              
        const 
        response
         =
         
        await 
        fetch(
        'https://api.github.com/repos/BuilderIO/qwik/pulls/1',
         {
        
       
                
        method:
         
        'GET',
        
       
              });
        
       
              
        if
         (!
        response
        .
        ok)
         {
        
       
                
        throw 
        new 
        Error();
        
       
              }
        
       
              
        const 
        json
         =
         
        await 
        response
        .
        json();
        
       
              
        setData(
        json);
        
       
              
        try
         {
        
       
              }
         
        catch
         (
        error)
         {
        
       
                
        console
        .
        error(
        error);
        
       
              }
        
       
            };
        
       
            
        getData();
        
       
          },
         []);
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        p
        >
        Hello,
         
        I'
        m
         
        a
         
        simple
         
        Client
         
        fetch
         
        React
         
        component
        </
        p
        >
        
       
              {
        data
         ?
         
        <
        pre
        >{
        JSON
        .
        stringify(
        data,
         
        null,
         
        2)}
        </
        pre
        >
         :
         
        Loading...}
        
       
            
        </
        div
        >
        
       
          );
        
       
        };
        
       
        export 
        default 
        ClientFetchReactComponent;
        
       |  
    
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        import
         {
         
        component$,
         
        useVisibleTask$,
         
        useSignal
         }
         
        from
         
        '@builder.io/qwik';
        
       
        const 
        ClientFetchQwikComponent
         =
         
        component$(()
         =
        >
         {
        
       
          
        const 
        data
         =
         
        useSignal(
        null);
        
       
          
        useVisibleTask$(
        async
         ()
         =
        >
         {
        
       
            
        try
         {
        
       
              
        const 
        response
         =
         
        await 
        fetch(
        'https://api.github.com/repos/BuilderIO/qwik/pulls/1',
         {
        
       
                
        method:
         
        'GET',
        
       
              });
        
       
              
        if
         (!
        response
        .
        ok)
         {
        
       
                
        throw 
        new 
        Error();
        
       
              }
        
       
              
        const 
        json
         =
         
        await 
        response
        .
        json();
        
       
              
        data
        .
        value
         =
         
        json;
        
       
            }
         
        catch
         (
        error)
         {
        
       
              
        console
        .
        error(
        error);
        
       
            }
        
       
          });
        
       
          
        return
         (
        
       
            
        <
        div
        >
        
       
              
        <
        p
        >
        Hello,
         
        I'
        m
         
        a
         
        simple
         
        Client
         
        fetch
         
        Qwik
         
        component
        </
        p
        >
        
       
              {
        data
        .
        value
         ?
         
        <
        pre
        >{
        JSON
        .
        stringify(
        data
        .
        value,
         
        null,
         
        2)}
        </
        pre
        >
         :
         
        Loading...}
        
       
            
        </
        div
        >
        
       
          );
        
       
        });
        
       
        export 
        default 
        ClientFetchQwikComponent;
        
       |  
    
 As you probably know, React’s useEffect has to return a function, not a promise. In order to fetch data asynchronously on page load, a useEffect with an empty dependency array needs to contain a function that can use async/await.
Qwik, however, has useVisibleTask — which can return a promise. useVisibleTask is only executed in the browser, but if you do want to use a similar approach for server-side data fetching, Qwik also has useTask.
These are just a few examples of the differences/similarities between React and Qwik, and I for one am really coming around to the Qwik way of thinking. For quite a long time now I’ve had what some describe as “React brain,” but taking a quick break from React impelled me to look around and see what the rest of the JavaScript mega-legends have been up to (Qwik was created by Angular creator Miško Hevery).
It might be scary even considering migrating away from React, but when thinking about what React was (a client-side state management library) and what it’s now being re-engineered to be… [insert your understanding here], now is probably a good time to investigate your alternatives.
No one knows what the future holds, but at the very least, Qwik was designed in the here and now to work in the here and now, and I’ve been really enjoying the experience so far. Go team Qwik!
