SvelteKit uses filesystem-based routing, which means that the routes of your app — in other words, what the app should do when a user navigates to a particular URL — are defined by the directories in your codebase.

Every +page.svelte file inside src/routes creates a page in your app. In this app we currently have one page — src/routes/+page.svelte, which maps to /. If we navigate to /about, we’ll see a 404 Not Found error.

Let’s fix that. Add a second page, src/routes/about/+page.svelte, copy the contents of src/routes/+page.svelte, and update it:

<nav>
	<a href="/">home</a>
	<a href="/about">about</a>
</nav>

<h1>about</h1>
<p>this is the about page.</p>

We can now navigate between / and /about.

Unlike traditional multi-page apps, navigating to /about and back updates the contents of the current page, like a single-page app. This gives us the best of both worlds — fast server-rendered startup, then instant navigation. (This behaviour can be configured.)