Canonical tag missing

What this means

Without a canonical tag, Google decides which version of your URL to index on its own. It might pick the www variant, a query-string copy, or a path with a trailing slash. The canonical tag is how you declare which URL is authoritative. Missing it means you are relying on Google’s guess.

How to fix it

Add an absolute rel="canonical" link to every public page pointing to its preferred URL.

Next.js App Router

Use the static metadata export for fixed pages, or generateMetadata for dynamic ones:

export const metadata = {
  alternates: {
    canonical: 'https://yourdomain.com',
  },
}

export async function generateMetadata({ params }: { params: { slug: string } }) {
  return {
    alternates: {
      canonical: `https://yourdomain.com/blog/${params.slug}`,
    },
  }
}

Next.js Pages Router

Use next/head inside each page component:

import Head from 'next/head'

export default function AboutPage() {
  return (
    <>
      <Head>
        <link rel="canonical" href="https://yourdomain.com/about" />
      </Head>
    </>
  )
}

SvelteKit

Use <svelte:head> in each page or layout:

<svelte:head>
  <link rel="canonical" href="https://yourdomain.com/about" />
</svelte:head>

For dynamic pages, use $page.url.href:

<script>
  import { page } from '$app/stores'
</script>

<svelte:head>
  <link rel="canonical" href={$page.url.href} />
</svelte:head>

Nuxt

Call useHead in your page or layout component:

useHead({
  link: [
    { rel: 'canonical', href: 'https://yourdomain.com/about' },
  ],
})

For dynamic pages, use useRequestURL:

const url = useRequestURL()
useHead({
  link: [
    { rel: 'canonical', href: url.href },
  ],
})

Astro

Pass the canonical URL through your base layout:

---
const { canonical } = Astro.props
---
<head>
  <link rel="canonical" href={canonical} />
</head>

---
import Layout from '../layouts/Layout.astro'
---
<Layout canonical="https://yourdomain.com/about">
  <!-- page content -->
</Layout>

Verify the fix

Check that the canonical appears in the rendered HTML:

curl -s https://yourdomain.com/ | grep canonical

Expected output:

<link rel="canonical" href="https://yourdomain.com/" />

Re-run orino audit to confirm the check passes.