Example

Swup requires two things to work: a content container with an id and an animation class, as well as corresponding transition styles it can wait for when loading a page.

We'll tackle these one by one. See below for the complete code and an interactive demo.

1. Content container

Let's mark our main element as a content container by adding the id #swup.

We'll also add a special animation class to let swup know that we want to wait for this element to finish animating whenever a new page is loaded.

<main id="swup" class="transition-fade">
  <h1>Welcome</h1>
  <p>Lorem ipsum dolor sit amet.</p>
</main>

<main id="swup" class="transition-fade">
  <h1>Welcome</h1>
  <p>Lorem ipsum dolor sit amet.</p>
</main>

2. Animation styles

Let's define a CSS transition on the special animation class added before:

/* Define a transition duration during page visits */
html.is-changing .transition-fade {
  transition: opacity 0.25s;
  opacity: 1;
}

/* Define the styles for the unloaded pages */
html.is-animating .transition-fade {
  opacity: 0;
}

/* Define a transition duration during page visits */
html.is-changing .transition-fade {
  transition: opacity 0.25s;
  opacity: 1;
}

/* Define the styles for the unloaded pages */
html.is-animating .transition-fade {
  opacity: 0;
}

For this example, we're using CSS to animate our page transition. Swup also supports JS animations and native View Transitions. Learn more about defining animations.

3. Initialize swup

Finally, we'll load and initialize swup. And we're good to go!

import Swup from 'https://unpkg.com/swup@4?module';

const swup = new Swup();

import Swup from 'https://unpkg.com/swup@4?module';

const swup = new Swup();

Complete example

Putting it all together, this is the complete code required for a basic swup setup.

<html>
  <head>
    <title>Swup Example</title>
    <style>
      html.is-changing .transition-fade {
        transition: opacity 0.25s;
        opacity: 1;
      }
      html.is-animating .transition-fade {
        opacity: 0;
      }
    </style>
  </head>
  <body>
    <main id="swup" class="transition-fade">
      <h1>Welcome</h1>
      <p>Lorem ipsum dolor sit amet.</p>
    </main>
    <script type="module">
      import Swup from 'https://unpkg.com/swup@4?module';
      const swup = new Swup();
    </script>
  </body>
</html>

<html>
  <head>
    <title>Swup Example</title>
    <style>
      html.is-changing .transition-fade {
        transition: opacity 0.25s;
        opacity: 1;
      }
      html.is-animating .transition-fade {
        opacity: 0;
      }
    </style>
  </head>
  <body>
    <main id="swup" class="transition-fade">
      <h1>Welcome</h1>
      <p>Lorem ipsum dolor sit amet.</p>
    </main>
    <script type="module">
      import Swup from 'https://unpkg.com/swup@4?module';
      const swup = new Swup();
    </script>
  </body>
</html>

Demo

Here's an interactive demo to try out the fade animation we've just built together.

Head to the demo page for more examples.

https://swup-demo-basic-temp.replit.app
Swup Demo: Basic

https://swup-demo-basic-temp.replit.app
Swup Demo: Basic