301 redirect
Definition
A 301 redirect tells browsers and search engines that a page has permanently moved to a new address. It is the key tool for rebuilding a website without losing its visibility.When you rebuild your website, your page addresses almost always change. Without precautions, every old address becomes a dead end: visitors hit a 404 error, and search engines lose track of pages they sometimes knew for years.
The 301 redirect solves exactly that: it says "this page has moved here, permanently". The visitor is taken to the right place without noticing, and the search engine transfers the history and reputation of the old page to the new one.
In a serious redesign, a redirect plan is drawn up: the complete map of old addresses and their destinations. It is meticulous work, but it is what protects years of accumulated visibility. A migration without a redirect plan is a house move without a forwarding address.
The complete method is detailed in our article migrating your website without losing your rankings.
After a launch, watch the 404 errors in Google Search Console for a few weeks: it is the surest way to spot a forgotten redirect.