Understanding Canonical URLs

In the world of Search Engine Optimization (SEO), duplicate content is a significant issue. Search engines get confused when multiple URLs lead to the same or very similar content. This confusion can dilute your page ranking and negatively impact your site’s visibility.

Enter the Canonical URL.

What is a Canonical URL?

A canonical URL is an HTML link element with the attribute rel="canonical". It tells search engines which version of a page is the “master” or preferred version.

<link rel="canonical" href="https://example.com/blog/canonical-urls" />

Why Should You Care?

Consolidates Link Signals: If multiple URLs point to the same content (e.g., example.com/blog?page=1 vs example.com/blog), search engines will know to attribute all ranking power to the canonical URL.
Manages Syndicated Content: If you publish your articles on other platforms like Medium or Dev.to, a canonical tag pointing back to your original post tells Google that your site is the original source.
Prevents Duplicate Content Issues: Even small variations like query parameters can be seen as separate pages. Canonical tags solve this.

Implementing in SvelteKit

In SvelteKit, adding a canonical tag is straightforward using <svelte:head>.

<script>
  export let data;
</script>

<svelte:head>
  <link rel="canonical" href={data.canonicalUrl} />
</svelte:head>

By ensuring every page has a self-referencing canonical tag (or points to the original source), you protect your SEO efforts and ensure your content gets the credit it deserves.