A redirect tells Google a URL has moved. Server-side HTTP redirects are the strongest and fastest to process.
Types
- 301 / 308 permanent, the destination replaces the original. Use for moves.
- 302 / 307 temporary, the original stays canonical. Use for genuinely short-lived changes only.
- meta refresh, supported but slow to process and poor for users.
- JavaScript redirect, only processed at render time, so it is the slowest signal of all.
Rules that avoid lost value
Redirect each old URL to its closest equivalent, not to the homepage, a mass redirect to the homepage is treated as a soft 404. Keep chains short; each hop adds delay and risk. Never create loops.
Alien Road recommends: map old URLs to new ones page by page before a migration, and keep the map in version control. On every migration we have rescued, the damage traced back to a wildcard rule that sent whole sections to the homepage because nobody had built the map.