Site Moving DayField notes on moving a website without breaking it

Note 04

Keeping old URLs working with 301 redirects

Last reviewed

In brief

  • A 301 redirect says "this page has moved for good".
  • Give every old address its own matching new address.
  • Test the redirects, and keep them for a long time.

Other websites, bookmarks and search results all point at your old addresses. If the page isn't there any more, people see an error. A redirect fixes that. It sends a visitor from the old address to the new one.

What a 301 does

A redirect has a number called a status code. The code 301 means "Moved Permanently". MDN says it shows the requested page has been permanently moved to the address in the Location header.[1]

You never see this happen. Browsers load the new address straight away.[2]

A visitor asks for the old address. The old address answers 301, moved for good. The visitor then reads the new address.
A 301 redirect sends visitors to the new address.

Google recommends permanent redirects, such as 301 and 308, when you can use them.[3]

Make a map first

Open the sheet from your inventory. For each old address, write the exact new one. Google says it's important to map old URLs to the new ones.[3]

A rule can do the work for many pages at once. For example, one rule could forward every /blog/... address to the same path on the new site.

You can set redirects up in your host's control panel, in a server file or in your CMS. Ask your host which way it supports.

Three mistakes to avoid

Chains. A chain is when page 1 goes to page 2, which goes to page 3. Google says to avoid chaining redirects.[3] Point page 1 straight at page 3.

Top: a chain where Page 1 goes to Page 2 and then Page 3. Bottom: a direct route where Page 1 and Page 2 both go straight to Page 3.
Point every old address straight at the final one.

Everything to the home page. Google says not to send many old addresses to one unrelated place, such as the new home page.[3] A visitor looking for shoes should land on shoes.

Left: three pages, shoes, hats and coats, all sent to the home page. Right: each of the three sent to its own matching page.
Send each page to its own match, not to the home page.

Loops. A loop happens when redirects keep following each other.[2] The page never loads. This often shows up right after you change a server setting.

Test and keep them

Google says to test the redirects.[3] Open a few old addresses by hand and see where you land. For many addresses, a short script can check the list.

Google also says to keep the redirects for as long as possible.[3] Don't delete them after a week.

Next: testing the new copy before anyone is sent to it.

Sources

  1. 301 Moved Permanently, MDN Web Docs (accessed 2026-11-05)
  2. Redirections in HTTP, MDN Web Docs (accessed 2026-11-05)
  3. Site Moves and Migrations, Google Search Central (accessed 2026-11-05)