React and Vue SPAs often inject canonical tags via JavaScript — which Googlebot sees only after rendering, with a processing delay. Here's how Next.js SSR handles canonicals correctly, how to manage e-commerce faceted navigation, and how to verify what Google actually sees.
Canonical tags and 301 redirects both solve duplicate content problems — but through different mechanisms with different trade-offs. Here's the decision framework for when to use each, common canonical mistakes, and the belt-and-braces approach for domain canonicalisation.
Learn what canonical tags are, why duplicate content hurts SEO, how to use canonicals vs. 301 redirects, and how to generate the correct canonical tag for any URL with a free tool.
