Moving to a new host without breaking anything

The steps, in order

1. Find out everything the old host does

   The website, certainly. But does the old host also handle your email, your domain registration or your DNS? Each of those needs its own plan, and email is the one people miss. If you aren't sure, the lookups in this guide will tell you.

2. Lower the TTL a day ahead

   Every DNS record has a TTL, the time other computers may keep a copy of it. A day before the move, set the TTL on the website's records to five minutes, which is 300 seconds. When you make the switch, visitors follow it within minutes rather than hours. Do it at least as far ahead as the old TTL, or the old value is still being held.

3. Copy the site

   The files and the database. For WordPress, a migration plugin does both, and many hosts will do the move for you when you join. Take a full backup from the old host at the same time and keep it yourself.

4. Test it on the new host before you switch

   Most hosts give you a temporary address. If not, you can make only your own computer see the new host by adding a line to its hosts file, which is C:\Windows\System32\drivers\etc\hosts on Windows and /etc/hosts on a Mac. The line is the new server's address followed by your domain, like the example below. Check every page and every form, then remove the line.

   203.0.113.10  example.co.uk  www.example.co.uk

5. Freeze changes

   From the moment you copy the site until the switch, nobody should edit it. If it takes orders or bookings, pick a quiet time, and be ready to copy across anything that arrives at the old host during the changeover.

6. Switch the website's records

   Change the website's DNS records to the new host's address. Change only those. Leave the mail records exactly as they are.

7. Let the new host issue a certificate

   A free certificate can usually only be issued once the domain points at the new host, so expect a short window when the secure address isn't ready. Check the site on https once it is.

8. Keep the old account for a week or two

   Some visitors and some mail servers will hold the old address for a while. Keep the old hosting running, check nothing is still arriving there, download a final backup, and only then cancel it.

If the email is moving too

Treat it as a separate project, on a separate day. The new mail provider sets up the mailboxes, the existing mail is copied across, usually over IMAP, and then the MX records are changed to point at the new provider. Keep the old mailboxes open until nothing new has arrived in them for a few days.

Tell staff beforehand. Phones and laptops will need the new account settings, and a mailbox set up on a phone years ago will quietly stop receiving if nobody updates it.