Preserving rankings when addresses change.
WHEN URLS CHANGE
A redesign with new structure Moving from http to https Changing domain Reorganising categories Changing a permalink structure
THE RULE
Every old URL must redirect to its closest new equivalent, with a 301 permanent redirect, in a single hop.
WHY A 301
It tells engines the move is permanent and transfers ranking signals. A 302 temporary redirect does not transfer the same way.
FINDING YOUR OLD URLS
Export from analytics, Search Console, and your sitemap before making changes. Afterwards is too late.
AVOIDING CHAINS
Redirect directly to the final destination. A chain of three redirects wastes crawl budget and loses signal.
WHAT NOT TO DO
Redirect everything to the homepage. Engines treat that as a soft 404 and you lose the ranking entirely. Redirect to the closest relevant page, or let it 404 if there is none.
AFTERWARDS
Monitor 404s in Search Console for a month. Anything appearing was missed.
Update internal links to the new URLs rather than relying on redirects.