When should I use a 301 redirect?

Redirect types, in short:

• 301 and 308: permanent. Search engines treat the target as the new address.
• 302 and 307: temporary. Use them when the original URL will come back, such as during short maintenance.
• Meta refresh and JavaScript redirects: work in some cases but are less reliable, so use server-side redirects where you can.

Good practice:

• Redirect each old URL to its closest equivalent. Sending everything to the homepage loses relevance and frustrates visitors.
• Avoid chains and loops by pointing old URLs straight at the final destination.
• Update internal links, canonical tags and sitemaps to use the new URLs, so your own site doesn't rely on redirects.
• Keep a mapping file so redirects survive future redesigns and platform changes.

Redirects matter most during migrations, where missing mappings are a common cause of lost traffic. Google's site move guidance recommends HTTP permanent redirects such as 301 and 308, kept for as long as possible and generally at least a year, so ranking signals can transfer to the new URLs.