--- title: "Canonical URL is relative or contains a fragment (seo/canonical-invalid)" description: "seo/canonical-invalid: Google asks for absolute canonical URLs; relative ones get resolved against unexpected bases (previews, proxies) and fragments are…" canonical: https://void-design.vercel.app/rules/seo/canonical-invalid lastModified: 2026-09-16 --- # Canonical URL is relative or contains a fragment `seo/canonical-invalid` · severity **error** · category SEO · detected by `void seo` and `void audit` ## Why it matters Google asks for absolute canonical URLs; relative ones get resolved against unexpected bases (previews, proxies) and fragments are ignored. This is a scoring gate. ## How to fix it Set metadataBase in the root layout so alternates.canonical becomes absolute, and never include #fragments. ## Example ```ts // app/layout.tsx export const metadata: Metadata = { metadataBase: new URL('https://acme.example') } ``` ## References - https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls ## More seo rules `void seo` reports 60 rules in this category. What search engines need from the raw response: status codes, titles and descriptions in , self-referencing canonicals, one h1, crawlable links, Open Graph, icons, robots.txt and a sitemap with real dates. - `meta-description-missing` No meta description in — [seo/meta-description-missing](https://void-design.vercel.app/rules/seo/meta-description-missing) - `meta-description-length` Meta description length outside 50–160 characters — [seo/meta-description-length](https://void-design.vercel.app/rules/seo/meta-description-length) - `metadata-in-body` Crawler receives /canonical/description inside <body> (Next.js streaming metadata) — [seo/metadata-in-body](https://void-design.vercel.app/rules/seo/metadata-in-body) - `canonical-missing` No single rel=canonical in <head> — [seo/canonical-missing](https://void-design.vercel.app/rules/seo/canonical-missing) - `canonical-broken` Canonical points to a URL that returns 4xx/5xx — [seo/canonical-broken](https://void-design.vercel.app/rules/seo/canonical-broken) - `canonical-conflict` Canonical target redirects, is noindex, or canonicalises elsewhere — [seo/canonical-conflict](https://void-design.vercel.app/rules/seo/canonical-conflict) - `canonical-not-self` Canonical points to a different URL — [seo/canonical-not-self](https://void-design.vercel.app/rules/seo/canonical-not-self) - `head-js-mutation` JavaScript changes canonical, robots, title or description after load — [seo/head-js-mutation](https://void-design.vercel.app/rules/seo/head-js-mutation) Detected by `void seo` and `void audit`. Explain it in a terminal: `void rules seo/canonical-invalid`