WordPress 5.9 Performance Improvements

WordPress is constantly being improved in order to provide a smoother, speedier, and more secure solution to users. Trying to keep up with every new update, such as the recent WordPress 5.9 “Joséphine” performance improvements, can feel a little overwhelming.

However, the latest release comes with a handful of noteworthy features. The update includes both front-end and editor enhancements that can help make working with the CMS an easier and more enjoyable experience.

In this post, we’ll explore five of the biggest performance improvements you can expect to see with WordPress 5.9. Let’s jump in!

Block Themes and Better Block Stylesheets

WordPress 5.9 is the first version of the CMS that supports Full-Site Editing (FSE) using block-based themes:

A WordPress block theme in the editor.

These block themes only contain a theme.json file. This means that all of the stylesheets on WordPress sites will be placed together.

There have also been some performance improvements to the block stylesheets. With WordPress 5.9, only the CSS of blocks required for viewing content will be loaded. This minimizes the amount of CSS loading on the page, which can help speed up you site.

Blocks can now register multiple stylesheets on each block, and load styles from other blocks when necessary. With this update, you’ll also be able to add styles for your themes on a per-block basis.

Lazy Render Applied to the Inserter Tool

The Inserter tool has been a powerful feature of the WordPress Block editor for quite some time. You can use it to select and insert blocks and patterns into your WordPress posts and pages:

The WordPress Inserter tool.

With WordPress 5.9 performance improvements, the Inserter tool will be optimized to be faster than ever. Moving forward, lazy-render is applied to two instances of the Inserter: when selecting the blocks and patterns, and when displaying categories.

Lazy Loading Image Enhancements

Another WordPress 5.9 performance improvement to look forward to is lazy loading for images. First introduced in WordPress 5.5, this feature previously degraded the Largest Content Painful (LCP) because it would lazy load almost all of the image. LCP is a metric that measures the time a website takes to fully load the largest element on a page, which is normally the hero image.

However, WordPress developers discovered that it’s possible to boost LCP and increase page speed by skipping the lazy loading of the first image on a page. In the latest release, WordPress will no longer lazy load the first image on singular and archive pages.

This enhancement can be particularly helpful and effective for themes using single-column post content. The developers also expect this enhancement to help the on-page content of block-based themes.

List View Tool That Scales With Content

Another editor-related WordPress 5.9 performance improvement is the List View. This tool can make navigating between layers of content and blocks easier. It’s located along the top of the editor’s toolbar:

The List View tool that is getting WordPress 5.9 performance improvements.

Similar to the Inserter, WordPress 5.9 has enhanced the List View tool. It now uses a windowing technique that simultaneously generates a set number of items, then automatically scales within the content.

Reusable Blocks That Are Easier to Save

WordPress Reusable Blocks make it easier for you to create and save blocks to use in the future. This reduces the amount of time you would otherwise have to spend adding and customizing a block each time you want to use it across your website:

Reusable blocks in WordPress.

However, if you have a large website with thousands of saved blocks, you may still spend a lot of time working with reusable elements. WordPress 5.9 changes this.

The developers implemented a change to include a method in which the tokenizer regular expression used in package block-serialization-default-parser is extracted. Then, it is used to match the first block boundary contained in the markup of a reusable block. This makes it easier for users to work with saved blocks.


To keep your WordPress site secure and performing optimally, it’s important to keep up with the latest releases. However, before you update your website, it helps to know what new features and functionalities you can expect to see. For WordPress 5.9, that includes both front end and editor enhancements.

To recap, here are the five major performance improvements introduced with the latest WordPress release:

  • Block themes and better block stylesheets
  • Lazy render applied to the Inserter tool to make it faster
  • Lazy loading image enhancements
  • List View tool that automatically scales with content for easier navigation
  • Reusable Blocks that are faster and easier to save

Do you have any questions about the WordPress 5.9 performance improvements? Let us know in the comments section below!

Leave a Comment

Your email address will not be published. Required fields are marked *