Migrate WordPress to a New Host Without Downtime

The zero-downtime migration method

1. 1

   Lower the DNS TTL first

   A day or two before the move, drop the domain's TTL (e.g. to 300 seconds). This is the step everyone forgets — if the TTL is still at the default hours-long value when you cut over, visitors keep hitting the old server long after you've switched.

2. 2

   Copy files and database to the new host

   Move everything and import the database. The old site stays live and untouched throughout — this is a copy, not a move.

3. 3

   Test on the new host before touching DNS

   Preview the new site using a hosts-file entry or the host's temporary URL. Click through pages, forms, checkout, and the admin. This is where problems surface safely, not in front of customers.

4. 4

   Fix serialized-data URLs properly

   WordPress stores some settings as serialized PHP, and a naive find-and-replace of the old domain corrupts it — broken widgets, lost settings, mixed content. Use a serialization-aware search-and-replace, not a raw SQL edit.

5. 5

   Cut over DNS, then keep the old host briefly

   Point DNS at the new server. Because the TTL is low, propagation is quick. Leave the old host running for a few days so any straggling cached DNS still resolves to a working site.

What actually breaks in migrations

• Serialized data, as above — the number-one cause of a migration that "mostly works" but has broken settings.
• Hardcoded URLs in theme files, page-builder content, or a CDN config still pointing at the old domain.
• Email, if it was tied to the old host — moving web hosting can silently break MX or SPF. Confirm mail still flows.
• File permissions and PHP version differing between hosts, which can throw errors the old server didn't.
• SSL, which needs to be issued and active on the new host before cutover or visitors get certificate warnings.

Migration questions