Most WordPress plugin updates are fine. The ones that aren’t rarely take the site down. More often a plugin ships new CSS or JavaScript, and something that used to look right quietly doesn’t: a header wraps on mobile, a button loses its style, a form label jumps out of place. Nobody notices until a customer does.
WordPress itself only catches the loud failures. WordPress 6.6 added automatic rollbacks for failed plugin auto-updates: as the feature proposal describes it, WordPress requests the homepage after the update and restores the previous version if it finds a PHP fatal error. That protects your homepage from a white screen. It does nothing about a page that loads fine but looks broken.
This guide covers a repeatable way to test plugin updates for that second kind of problem, and the hosts and tools that can do the visual check for you.
Why plugin updates break how a site looks
Plugins don’t stay in their own box. Most load CSS or JavaScript on every page, so an update can change pages the plugin has nothing to do with. The usual causes:
- New or changed styles. A new class name, a reset, or a more specific selector that overrides your theme.
- JavaScript conflicts. A new version of a shared library, or a script that now loads in a different order.
- Page builders and their add-ons. An update to Elementor, Divi or an add-on pack changes how widgets render.
- Caching and optimisation plugins. Turning on minification, combining files or lazy-loading can reorder styles or hide content.
- Forms and embeds. Form plugins, CAPTCHAs and third-party scripts change their markup, and the page around them still loads.
In our study of 100 visual bugs that site teams marked in Diffy on live websites, 35 were layout shifts and misalignment, 10 were on forms, and only 2 were full error pages. Those are exactly the problems a fatal-error check can’t see.
A safe way to update WordPress plugins
1. Read what’s changing
On the Plugins screen, open each plugin’s details and check the changelog. A jump in the major version number, a note about a redesigned admin, or new “Requires WordPress” or “Requires PHP” versions are all reasons to update that plugin on its own rather than in a batch.
2. Back up first
Take a full backup, files and database, that you know how to restore. Most managed hosts take one on demand; otherwise use your backup plugin. A backup you’ve never restored is a hope, not a plan.
3. Update on staging, not production
Most managed WordPress hosts give you a staging copy. Refresh it from production so it has current content, then run the updates there. If you don’t have staging, update outside busy hours and have the backup ready.
4. Take “before” screenshots
Before you click update, capture the pages that matter at the widths your visitors use, at least one mobile and one desktop width. You don’t need every post. You need one or two pages per template:
- the homepage
- a standard page and a blog post
- an archive or category page
- a product page, the cart and the checkout, if you run WooCommerce
- every page with a form: contact, sign-up, donation
- any landing page built with a page builder
- search results and the 404 page
5. Run the updates
Update the risky plugins one at a time and the minor ones together. Clear any page cache and your CDN cache afterwards, or you’ll be comparing the old site with itself.
6. Take “after” screenshots and compare
Capture the same pages at the same widths and compare them side by side. Look for anything that moved, disappeared or changed style. Then check what screenshots can’t: submit each form, add a product to the cart, log in, and open the browser console for new JavaScript errors.
7. Push to production and check again
When staging looks right, apply the same updates to production and repeat the comparison on the live site. Production has things staging often doesn’t, such as a CDN, real caching and third-party scripts.
8. Decide what auto-updates may touch
Auto-updates are worth having for security fixes, but every auto-update is an untested change. Since WordPress 5.5 you can turn them on plugin by plugin from the Plugins screen. Leave them on for simple plugins, turn them off for page builders, checkout and form plugins, and schedule visual checks of production so you hear about changes nobody deployed.
Doing the visual check by hand
Comparing screenshots by eye works for a five-page brochure site. It stops working quickly. Ten pages at two widths is 20 pairs to compare, and a one-pixel shift or a missing consent line is easy to miss when you’re looking at the 18th pair. That’s why most agencies doing monthly maintenance automate the comparison.
Hosts and tools that check updates visually
Several managed hosts and site-management tools now run a visual check as part of their update process. They differ in where they work, how many pages they check and whether they roll back on their own. Each entry below comes from the vendor’s own site or documentation, checked on 5 November 2026.
| Tool | Where it works | What it checks | Rollback | Price |
|---|---|---|---|---|
| WP Engine Smart Plugin Manager | WP Engine hosting | 10 pages by default, up to 20, desktop and/or mobile, before and after | Automatic on a failed visual test or a 4xx/5xx error (can be turned off) | Included with Managed Hosting Plus, Secure Hosting and eCommerce; an add-on on Shared and Premium |
| Kinsta Automatic Updates | Kinsta, set up in MyKinsta | Homepage plus 4 random sitemap pages, or up to 5 pages you choose, before and after | Automatic, from the pre-update backup | $3 per environment a month, after a 31-day free trial |
| Cloudways SafeUpdates | Cloudways only | Before and after screenshots, on a temporary staging copy | Automatic, to the latest backup | $3 per application a month for 1–5, $2 for 6 or more |
| Pantheon Autopilot | Pantheon, WordPress and Drupal | Visual regression tests in an isolated Multidev | None: failed tests stop for review; passing updates deploy to Dev, Test or Live if you set it to | Gold accounts or higher, and agency partners |
| WP Remote | Any host, through its connector plugin | Home page on Essential, 5 pages on Premium, 25 pages plus mobile on Advanced | Manual, one-click restore of the backup | $1.99, $4.99 or $14.99 per site a month |
| WP Umbrella | Any host, through its connector plugin | Before and after, in its Advanced Safe Update mode | Optional: automatic if a visual issue is detected | $2.19 (€1.99) per site a month, one plan |
| ManageWP Safe Updates | Any host, through its connector plugin | One chosen page, side by side for you to review | Automatic only on a 4xx or 5xx error | Comes with the premium Backup add-on (from $2 per site a month); free on GoDaddy hosting |
| Diffy | Any host, from URLs | Every page in your project, at every breakpoint you choose | None: it compares, you decide | Free for 500 screenshots a month, then from $67/month billed annually |
A few things the table hides:
- Host tools only work on that host. If your sites are spread across hosts, as most agency portfolios are, you’ll need a different tool for each, or one that works anywhere.
- “Pages checked” varies a lot. One page catches a broken header. It won’t catch a broken checkout or a contact form three clicks deep.
- Automatic rollback is only as good as the check. A rollback on a visual change also rolls back updates that changed something on purpose, and a check that doesn’t run on a page can’t roll anything back.
WP Remote also offers Sandbox updates on its Advanced plan, which try the update on a private copy first. BlogVault has visual checks on updates too; we compare it in Diffy vs BlogVault.
Testing plugin updates with Diffy
Diffy is ours, so this section is about how we’d do it. Diffy doesn’t update plugins, take backups or roll anything back. It does the comparison in step 6, for as many pages and breakpoints as you need, on any host.
- Create a project and import your pages from
/wp-sitemap.xmlor your SEO plugin’s sitemap, then keep one or two pages per template. - Add staging as a second environment if your host gives you one. Diffy swaps the domain in every URL, so you keep one page list for both.
- Take a set of screenshots before you update.
- Run the updates, clear the caches, and take a second set.
- Compare. Diffy shows every page and breakpoint that changed, with the difference highlighted, and you mark each one as a bug or as expected.
If you’d rather start from inside WordPress, the free Diffy plugin can take the before and after screenshots for you from the Plugins screen.
What it costs. Diffy counts one page at one breakpoint as one screenshot. Fifteen pages at three breakpoints is 45 screenshots a set, or 90 for a before-and-after comparison. Four update rounds a month is 360 screenshots, which fits the free plan of 500 a month. For more sites, paid plans start at $67/month billed annually ($80 monthly) for 2,000 screenshots. See pricing.
Between update rounds, a schedule can screenshot production on the days you choose and tell you by email, Slack or webhook when something changes, which covers auto-updates and changes nobody deployed.
Frequently asked questions
Should I turn on auto-updates for WordPress plugins?
For simple plugins and security releases, usually yes. For page builders, checkout, membership and form plugins, it’s safer to update them yourself on staging and check the pages first. Since WordPress 6.6, a plugin auto-update is rolled back if it causes a PHP fatal error on the homepage, but WordPress doesn’t check how your pages look, or any page other than the homepage.
How do I test a plugin update without a staging site?
Take a backup, update outside busy hours, and compare screenshots of your key pages before and after the update so you can restore quickly if something changed. A staging copy is still the better option, and most managed hosts include one.
Which pages should I check after a plugin update?
One or two pages per template, plus every page with a form or a checkout step: the homepage, a page, a post, an archive, product, cart and checkout pages on WooCommerce, contact and sign-up forms, page-builder landing pages, search results and the 404 page. Check each at a mobile and a desktop width.
Do any WordPress hosts run visual regression tests on updates?
Yes. WP Engine’s Smart Plugin Manager, Kinsta’s Automatic Updates add-on, Cloudways SafeUpdates and Pantheon’s Autopilot all compare screenshots as part of their update process. Each works only on its own hosting. WP Remote, WP Umbrella and ManageWP aren’t tied to one host: they connect to your WordPress site through a plugin.
Can Diffy roll back a plugin update?
No. Diffy compares screenshots and shows you what changed. To undo an update, restore your backup or reinstall the previous plugin version.
Start with your next update
Before your next round of plugin updates, add the site to Diffy, take a set of screenshots, run the updates and compare. The free plan covers a small site’s monthly updates, and you’ll see exactly what changed instead of hoping nothing did.
Try Diffy free: 500 screenshots a month, no test suite required.
Related reading: WordPress visual regression testing · What breaks during WordPress and Drupal updates · The most common visual bugs that reach production