JavaScript redirect
A redirect performed in JavaScript after load depends on rendering and can be slow or missed. Where I can, I move it to the server so it happens before anything renders.
Redirect performed in JS after load.
Why it matters
Google can follow JS redirects but only after rendering, which is slower and less certain than an HTTP redirect.
How to fix it
Prefer server-side HTTP redirects for critical paths.
How to find it on your site
- Load the page with JavaScript disabled and see whether the redirect still happens.
- Check the page source for location changes inside scripts.
- In Search Console URL Inspection, see how Google resolves the URL.
- Replace with a server-side redirect wherever the destination is known up front.
Cross-reference to ranking and citation factors
Server-side redirects are seen immediately and pass signals cleanly. JavaScript redirects rely on rendering and are slower and less certain.
Impact
Medium-high reliability risk. Direct (documented as supported-but-slower).
Evidence
Google follows JS redirects but server-side is more reliable. Google Search Central, Redirects and Google Search; Google Search Central, Understand JavaScript SEO Basics
Sources