WordPress 5.9 update will not break websites with old themes

WordPress 5.9 will be released on 25^th January 2022 and there are a lot of concerns on whether updating to 5.9 will break websites using themes that do not support full site editor (FSE).

Will WordPress 5.9 update brake websites?

We have tested WordPress 5.9 with some of the most popular WordPress themes that have not implemented full site editing (FSE) and we have not found any problems.

For now, full site editing (FSE) will only be enabled for WordPress Themes that support FSE. WordPress has also made it easy to revert to WordPress 5.8.3 from the wp-admin dashboard if WordPress 5.9 breaks your website. To roll back to WordPress 5.8.3 use this procedure (WordPress core rollback).

NOTE: If you are using block plugins or your theme has built-in page builders like Elementor, then you might want to wait for about two weeks (for plugin updates) before updating to 5.9. This is because outdated block plugins are likely to conflict with FSE.

What if my theme does not support WordPress 5.9 FSE?

If you update your website to WordPress 5.9 and your theme does not support full site editing (FSE) then you will not be able to see FSE options. Your editing experience will remain as it was before the update. However, your website will load faster because of the performance features that were introduced in WordPress 5.9.

Major Changes in themes that support WordPress 5.9 FSE

• Customize: The customize option that was available under Appearance is now integrated in editor under styles options. To customize your theme you need to click Appearace>Editor>Then Styles (as show in the image below).

• Theme Editor which was under appearance is still available but has now been moved under the Tools tab called (Theme File editor).
• Menus can be accessed through clicking the Editor tab under appearance then once the full editing page section opens double click the page name on the right side of the website logo or name to add more pages or categories to the navigation menu.

NOTE: The three changes mentioned above are only noticeable for themes that support FSE. If your theme does not support FSE then everything remains the same (as it was in 5.8.3)

About full site editing (FSE) in WordPress 5.9

Full site editing (FSE) is the editor (accessed as shown in the image above) that is used for customizing your entire website look instead of editing your theme files. It brings almost the same experience offered by page builders like Elementor and Beaver Builder.

FSE is still in beta which means there are very few themes that support it. The best way to test the difference between a theme that supports full site editing and a theme that does not is to install the Twenty Twenty-Two theme.