You often meet sites where updates are postponed out of fear. Postponing does not remove the problem, it accumulates it. The version gap widens, so each update changes more at once and becomes more frightening — while every published vulnerability in between stays open.
The real reason updates feel frightening is not knowing what will break. There is a way to know, and then updating becomes an ordinary procedure with a fixed order.
1. Keep a list of what you overrode
The only things that can break are the places you reached into the parent. There are three kinds: templates copied into the child theme, CSS aimed at parent selectors, and code attached to parent hooks.
That is why part four asked you to note the source version in every copied file. Those comments are your diff list at update time. Without them you have to re-read the entire theme on every release.
2. Read the changelog first
Update notices usually carry a list of changes. Three kinds of entry matter to a designer.
A line about renamed classes is the dangerous one. The site keeps working while only your styles quietly miss their targets, and nobody notices until someone mentions days later that the spacing looks odd.
On a premium theme, also check that the licence is still active. These usually run yearly, and once it lapses the update notices stop arriving — which is easy to misread as “there are no updates”.
3. Work in order
Back up files and database together. It feels like rolling back the theme alone would be enough, but updates sometimes convert stored theme settings to a new structure, so you need the pair.
Staging means a copy configured like production. Update there first and look at it. If a copy is out of reach, at minimum do it at your quietest hour with the rollback ready.
Comparing screens is done by eye. Before updating, screenshot the pages that matter — home, a service page, one article, the contact form, and a mobile view — then place the post-update versions beside them. Those five catch most regressions.
After the update
Two more things beyond the visuals. Check that the parent stylesheet handle you depended on still exists — if it was renamed, your styles still load but lose their place in the order — and diff your copied templates against the new parent files. The second can wait, but a deferred diff doubles at the next release.
The wider procedure for keeping updates safe lives in the development workflow archive, and the actual working flow, staging and regression checks included, is published step by step on our process page.
Next part
Part seven is about page builders: what you give up in exchange for easier editing, and where to draw the line so you can keep both.