Excessive DOM size can negatively impact your website’s performance, particularly on load times and SEO. A large DOM (Document Object Model) size can slow down rendering, cause layout shifts, and contribute to poor Core Web Vitals, particularly for metrics like Cumulative Layout Shift (CLS) and Largest Contentful Paint (LCP). Google PageSpeed Insights often flags this issue as “Avoid an excessive DOM size.” This guide will walk you through the reasons for excessive DOM size in WordPress and provide actionable steps to fix and reduce it.
What is DOM Size?
The DOM is essentially the structured representation of your website’s HTML elements that browsers use to render pages. DOM size refers to the number of nodes (elements) within the DOM tree. When the DOM size is too large, it takes browsers more time to process and render the content, resulting in slower page loads. A DOM size can become excessive when it includes thousands of elements, deeply nested structures, or unnecessary divs and elements that increase complexity without providing any real value to the page.
Why Excessive DOM Size is a Problem?
The larger the DOM, the longer it takes for a browser to process and render the page.
Impact on Core Web Vitals: Google’s Core Web Vitals, such as Cumulative Layout Shift (CLS) and Largest Contentful Paint (LCP), can suffer when the DOM is too large.
Poor User Experience: A large DOM can result in layout shifts and a poor user experience, especially on mobile devices.
Lower SEO Rankings: Page speed and user experience directly affect SEO rankings. If your website loads slowly due to excessive DOM size, it can negatively impact your position in search results.
Know more: How to Measure the Success of Your Managed SEO Efforts
How to Identify Excessive DOM Size in WordPress?
Run a performance audit using Google PageSpeed Insights to check if your website is flagged for “Avoid an excessive DOM size.” This tool will give you insights into the number of elements in your DOM.
Lighthouse Audits: Lighthouse in Chrome DevTools can show you the number of DOM elements and whether the DOM size is excessive.
Browser Developer Tools: In most browsers (e.g., Chrome, Firefox), you can open DevTools (F12 or right-click > Inspect), and in the “Elements” tab, you can explore the structure and size of the DOM.
Third-Party Tools: Tools like GTMetrix and WebPageTest also provide insights into your website’s performance, including DOM size issues.
Read: Caching Plugins and Their Impact on SEO Performance
Common Causes of Excessive DOM Size in WordPress
While popular page builders like Elementor, WPBakery, and Divi offer a lot of flexibility, they often generate bloated HTML code with deeply nested elements, which increases DOM size.
- Overuse of Widgets or Shortcodes: Too many widgets, shortcodes, or unnecessary elements can inflate the DOM.
- Heavy Plugins: Plugins that add extra elements, like sliders, galleries, or pop-ups, can significantly contribute to a large DOM.
- Deeply Nested HTML Elements: Having too many deeply nested
divtags, sections, and containers can unnecessarily complicate the DOM. - Excessive Ads or Tracking Scripts: Multiple ad placements and tracking scripts often result in a high number of DOM elements.
- Auto-generated Content: WordPress themes or plugins that generate a large number of categories, tags, or recent posts may contribute to a bloated DOM.
Also read: Best Practices for Security in Enterprise WordPress Development
Steps to Fix Excessive DOM Size in WordPress
Here’s how you can fix the excessive DOM Size in WordPress issue:
Audit Page Builders and Themes
Page builders often introduce unnecessary nesting of div tags. While they make web design easier, they may inflate the DOM significantly.
Solution: Audit your use of page builders like Elementor, Divi, or WPBakery. Try to limit the use of complex layouts with deeply nested structures.
- Reduce unnecessary sections: Break down complex layouts and avoid over-nesting of rows and columns.
- Use lightweight themes: Switch to a more performance-optimized theme like GeneratePress or Astra, which are designed with fewer DOM elements.
- Optimize templates: Simplify templates by reducing sections, widgets, and unnecessary elements that may contribute to DOM bloat.
Minimize Use of Widgets and Shortcodes
Excessive use of WordPress widgets or shortcodes, such as social media feeds, recent posts, or carousels, can increase the DOM size.
Solution: Minimize the use of unnecessary widgets, sidebars, and shortcodes. For example, if you have a “Recent Posts” widget that displays 20 items, reduce it to 5-7 items.
- Disable unused widgets: Turn off widgets that aren’t essential to your page’s functionality.
- Use optimized shortcodes: Choose lightweight shortcode options if available or custom code optimized versions.
Learn: Fixing The Deadliest White Screen Of Death In WordPress
Limit Plugin Usage
Plugins that add multiple elements to your pages (such as sliders, galleries, or pop-ups) can bloat your DOM. Plugins that create unnecessary extra divs and sections can severely inflate the DOM.
Solution: Deactivate plugins that add unnecessary complexity to your site, and replace them with lighter alternatives.
- Replace heavy plugins: For instance, use lightweight sliders or galleries, such as MetaSlider instead of Slider Revolution.
- Consolidate plugins: Use multifunctional plugins that reduce the need for multiple different ones.
Simplify HTML Structure
A common cause of excessive DOM size is deeply nested elements. This often occurs when themes or page builders create multiple layers of div tags, sections, or containers.
Solution: Manually clean up your HTML structure by simplifying the page layout and reducing the depth of nested elements. If possible, modify the theme or page builder’s output to reduce unnecessary containers. Use fewer div elements and clean up redundant code.
Learn about: Best WordPress Backend Optimization Techniques
Optimize Ad and Script Loading
If you are running ads or third-party scripts, they can introduce additional DOM elements.
Solution: Limit the number of ads or tracking scripts on your pages and lazy load ads to reduce initial DOM load.
- Lazy load ads: Use ad management plugins or scripts that support lazy loading to reduce the number of DOM elements loaded initially.
- Minimize tracking scripts: Review third-party tracking and remove any that are not necessary.
Optimize Menus, Categories, and Tags
Overly complex navigation menus, categories, or tags can introduce many DOM elements.
Solution: Simplify your menu structure and limit the number of categories, tags, or links displayed at once.
- Reduce menu items: Keep menus concise and avoid deep dropdowns.
- Limit category/tag display: Use pagination or “load more” features to avoid displaying large numbers of categories or posts at once.
Lazy Load Images and Videos
Loading all media elements at once increases the DOM size, particularly on media-heavy pages.
Solution: Implement lazy loading for images and videos, so that they only load as users scroll down the page.
- Use plugins: Utilize a lazy loading plugin or native WordPress lazy loading features for images and iframes.
- Reduce media elements: Limit the number of images and videos on a single page.
Minify and Combine CSS and JavaScript
Excessive styles and scripts can contribute to a larger DOM size by adding extra elements, IDs, and classes.
Solution: Minify and combine CSS and JavaScript files to reduce the number of elements and simplify the code. Plugins like Autoptimize can minify and combine your CSS and JavaScript, reducing the overall DOM complexity.
Find out: Different CMS Platforms: Features and Benefits
Conclusion
Excessive DOM size can hinder your website’s performance, lead to slower loading times, and negatively impact SEO rankings. Fixing this issue requires optimizing your WordPress site by reducing unnecessary elements, simplifying the HTML structure, minimizing plugin usage, and optimizing page builders, ads, and media elements.
By implementing the steps outlined above, you can reduce the DOM size of your WordPress site, improve page speed, and enhance the overall user experience, which will ultimately benefit your SEO and conversion rates. Regular performance audits and proactive measures are essential to maintaining an optimized and user-friendly site.