The WordPress update checklist (one page)

Why WordPress updates go wrong

Updating WordPress is usually uneventful, and when it is not, the cause is almost always the same few things: two plugins that disagree after one of them changes, a theme that overrides something core has changed, a PHP version that is too old or too new for a plugin, or no recent backup to return to. A little order before and after removes most of the risk.

The safe order

1. Confirm a recent backup exists and that you could restore it. Do not start without one.
2. Use a staging copy if you have one, especially for a store, a booking site or a site with many plugins.
3. Update WordPress core first, then your themes, then your plugins, one group at a time, so that a problem is easy to trace.
4. Check the site after each group, not only at the end.

What to check afterwards

Open the home page and two inner pages. Submit a form. Log in and log out. If the site takes orders or bookings, do a test order or booking. Look at the page on a phone. In the admin area, look for new warnings or notices. If anything looks different, stop and find out why before you update anything else.

When not to update straight away

• A plugin whose maker has not updated it for a long time. It may work today and break the next time WordPress changes.
• A heavily customised theme, where an update may wipe changes that live in the theme files.
• A large jump in a major version of a plugin that handles money, bookings or memberships.
• The middle of a sale, a launch or a busy week.

In these cases, tell whoever owns the site what you found, what the risk is and what you suggest, and wait for a yes before changing anything.

If something breaks

Stay calm and change one thing at a time. Restore the backup if the site is down. If you cannot reach the admin area, a common fix is to rename the folder of the plugin you just updated through your host's file manager, which switches it off, then log in and look. If you do not know what you are looking at, stop and ask for help early, because each extra change makes the cause harder to find.

The one-page list is below. Print it and keep it where you do the updates.

Keep this next to your desk. It is the routine we follow for every WordPress update, in a form you can tick off.

Before you start

• A recent backup exists and you know how to restore it.
• You have picked a quiet time for the update.
• You have noted how the home page, a key page and your main form look now.

The updates, in this order

• Test on a staging copy first, if you have one.
• Update WordPress core.
• Update the theme, then check the pages.
• Update plugins in small groups, and check the site after each group.
• Test your key pages and your contact or booking form.
• On a store, place a test order from the cart to the confirmation.
• Release to the live site.
• Look again after release.

If something breaks

• Write down exactly what is wrong and where.
• Undo the last change or the last group of updates.
• Restore the backup if undoing is not enough.
• Find the cause before trying again. Often it is a plugin that has not kept pace with WordPress, or two plugins that clash.
• Write down what happened, so the next update is safer.

Do not update blindly

A plugin that its maker has not updated for a long time, or a heavily customised theme, can break when touched. Decide what to do about those first.

Want it handled for you? See WordPress maintenance.