Switching to another host sounds scary, but with some planning you can migrate without downtime or data loss. The key is the order of the steps and testing the new site before you redirect traffic to it. The most common reason to move is a higher renewal price or dissatisfaction with performance — and neither is a reason to fear the migration.
Preparation and backup
Before you move anything, make a complete backup — both the site files and the database. Also write down a list of email mailboxes and DNS records so you don't forget anything. This preparation will save you hours of searching later. If you haven't got backups sorted yet, go through How often to back up your website — the ability to restore a site from a backup is exactly what you'll use during migration.
Transferring data and testing
Upload the files and database to the new host and test the site before switching DNS — either via a temporary domain or by editing the hosts file on your computer. Verify that forms, login and links work. This phase is the most important: as long as you haven't switched DNS, visitors still go to the old server and you have time to fine-tune everything calmly.
Lower the TTL in advance
The day before migration, lower the TTL on your DNS records to a few minutes. The change will then propagate faster after the switch, and the window during which some visitors hit the old server will be minimal.
Switching and checking
After testing, switch DNS to the new server. Leave the old host running for a few more days until the change propagates everywhere. Finally, check indexing in search engines and that email works, so the migration affects neither SEO nor mail delivery.
Common mistakes you'll avoid
Most migration problems arise not from technical complexity but from inattention. The most common is forgetting about email — people watch the site but overlook the mail and its DNS records (MX), and suddenly messages stop arriving. The second classic is deleting the old host too soon, before the DNS change has propagated everywhere; leave it running for at least a few days. And third, it pays to check that the PHP and database versions match on the new server — a site built on a newer PHP may not start on an older one.
Don't forget about SEO
If you don't change the page addresses during migration, search engines will barely notice the server change. Even so, after switching it pays to check that the site is indexed correctly and that no "block robots" left over from the testing phase remains — an accidentally kept "disallow indexing" can drop the site from search results. A short check after migration spares you that unpleasant surprise.
It's a different situation if you change the page addresses or the domain during migration. Then you need to set up redirects (301) from the old addresses to the new ones, so their value for search engines carries over and visitors don't hit error pages. Without redirects you'd lose the positions you've built up in search over the years. If you're also changing the domain registrar, go through How to transfer a domain to another registrar.
Migrating hosting vs transferring a domain
Migrating a website and transferring a domain are two different things that are often confused. In a migration you move the site and mail to a new server (DNS changes), whereas in a domain transfer you only change the registrar the domain is held with. You can do just one of them, or both at once. How to handle the domain transfer itself without downtime is described in How to transfer a domain to another registrar, and how much the new hosting will cost you can be worked out from How much does running a website cost per year.
Once you separate the two concepts, migration loses most of its scariness. It's not one big risky step but a series of small, controllable ones: backup, transfer, test, lower the TTL, switch and check. You can verify each one calmly and only then continue. That's exactly why even an ordinary user can move a website, as long as they don't rush and stick to the order of the steps.