Moved Permanently

The resource has a new permanent URL. Update your links.

301 Moved Permanently tells clients and search engines that a resource now lives at a new URL for good. Browsers cache it aggressively, so a wrong 301 can be painful to undo. For SEO, a 301 passes nearly all ranking signal to the new URL, which makes it the right choice when you rename or restructure pages.

What 301 looks like on the wire

GET /old-pricing HTTP/1.1
Host: example.com

HTTP/1.1 301 Moved Permanently
Location: https://example.com/pricing
Cache-Control: max-age=31536000

About 3xx Redirection

Further action is needed to complete the request, usually following a redirect to another URL.

How to fix 301 Moved Permanently

Set the Location header to the new, absolute URL.
Use 301 (not 302) when the move is permanent so link equity transfers.
Double-check the target before shipping - browsers cache 301s for a long time.
Avoid redirect chains: point old URLs straight at the final destination.

Tools that help with 301

URL Builder & Parser

Paste the old and new URLs to compare their parts side by side before you update links and bookmarks.

Where it's defined

301 Moved Permanently is defined in RFC 9110 §15.4.2. MDN's 301 reference covers browser behavior and examples.