Case Study

WordPress Customizer

Building the live preview interface for 30% of the internet.

For the last 4 years we’ve led the development of the WordPress Customizer, bringing users of the world’s most popular CMS a live site-editing and previewing interface.

Our Contribution

  • Technical Lead
  • Project Management
  • Development
  • UX

The Story

Our Customizer journey has been one taken hand-in-hand with our clients. With the value to their business in mind, we’ve looked beyond what was presently possible and broke new ground, influencing WordPress Core and its millions of users.


In 2013 we worked on a prototype for a client that demonstrated how WordPress widgets and the Customizer could be used to provide a drag-and-drop live preview page building experience. At the time widgets were not available in the Customizer, so we worked to combine the drag-and-drop experience of the widgets admin screen to the interface of the Customizer. Out of that came the Widget Customizer feature plugin, and in WordPress 3.9 this was merged into WordPress core.


In 2015 we started working with News Corp Australia on what was, at the time, the largest ever WordPress migration. The experience of facilitating complex, multi-user editorial workflows across 15 publishing brands unearthed some of the shortcomings of the WordPress experience for previewing and managing site and content changes. Beyond just having a drag-and-drop live-preview editing experience in WordPress, there was also the need to allow users to save a draft of their changes to come back to later. Out of this, the Customize Snapshots feature plugin was born and in WordPress 4.7 and 4.9 this plugin was adapted for core merge.


In 2016 we partnered with Beachbody to refine their content editorial workflows. Beachbody provide fitness, nutrition, and support to customers all over the world through a library of workout programs, an extensive online coaching network, and nutritional supplements. The content types and structure were complex and their distribution through multiple channels stretched the capabilities of out-the-box WordPress. We worked closely with their internal teams to enhance the Customizer, leveraging its JavaScript core, to significantly improve the entire multi-channel content publishing experience.


Customizer, alongside the changes coming to WordPress through the Gutenberg editor, represents a key piece of what will strengthen the future of WordPress as a dynamic and flexible CMS. This is why we continue to commit resources to its development, supporting our mission of building a better open web.

The Customizer lets WordPress users build and edit their site with confidence, knowing nothing goes live until they’re ready. Effectively, it equips them to build a better version of their corner of the web. This is why we are so committed to its development.

Derek Herman, Chief Technology Officer @XWP

The Impact

The Customizer represents a major stride in the modernization of WordPress. For the end user it has laid a foundation for previewing, batching, staging, and scheduling site changes. Under the hood it represents the beginning of JavaScript’s importance in WordPress core, foreshadowing future JavaScript-led components like the Gutenberg editor.

While the Customizer’s real-time content previewing and general site customization control has been incredibly useful to all levels of WordPress users, perhaps its value is most clear in large-scale WordPress sites with complex editorial workflows. Controlling what can be changed, who can do it, how it’s done, and when it’s published, all within a friendly interface on the production environment has been an efficiency game changer for businesses like the large publishers we serve. Further, the extension plugins we build enabling content scheduling, batch previewing and live editing hooking into the Customizer means that WordPress as a platform’s limits are nearly boundless. While it may have started with News Corp Australia, Customizer continues to be a thread that weaves its way through almost all of our client projects.

The Customizer’s true power lies far beyond the ability to just tweak a site’s design: the Customizer provides a framework for live previewing any change to a site, including changes to content. Essentially the Customizer brings a staging environment to production, where changes across a site can be previewed and published together.

Weston Ruter, Google Developer Relations @XWP Alumni

The Future

In December 2016, during the annual State of the Word presentation, Matt Mullenweg announced a change to the release cycles of WordPress: A move away from date-dictated releases to feature and component focused releases. The focus for the coming years would be grouped under the REST API, Editor, and the Customizer.

The Customizer’s role in the future of WordPress is wide-reaching. The incoming update to the WordPress editor is another major step in the maturing of WordPress as a platform and the integration (in some places merger) of the two components will be the focus for the coming release cycles. These two layers of technology will continue to develop and slowly, but surely, become thought less of as features and simply become part of the whole WordPress user experience.

As we have for the last 4 years, we continue to devote time, resources, and passion to improving the WordPress Customizer. The value it brings to our clients and partners has been proved time and time again, and we look forward to working with, and on, the Customizer in our pursuit of a better open web.

Key Takeaways

  • Technical leadership on Customizer
  • A rich previewing experience
  • Deep value across at-scale projects

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We can help you leverage the Customizer to streamline your editorial and site management workflows. Find out how.