Speed is king. A slow visitor experience can break your website. Most websites on a CMS can become unbearably slow because they get too complex, causing excessive Document Object Model (DOM) size.

DOM is made up of all the layouts on your page (such as templates, modules, layouts, and scripts). Often overlooked, the size of your page's DOM significantly impacts how fast users browse your site. Excessive DOM size affects everything from load times to website performance scores. Let's take a look at how a hefty DOM could be weighing down your website and what you can do to lighten the load.

What Is the DOM and When Does It Become Excessive?

For those who might not be developers or familiar with the practice, the DOM is essentially the structural blueprint of your webpage. It's a representation of your HTML, CSS, and JavaScript files that the browser uses to render your site. When users load a page, the browser constructs this model to display all elements correctly.

However, if your DOM becomes excessively large (think thousands of unnecessary nodes) it can cause your site to become sluggish. This can lead to longer load times, increased memory usage, and a frustrating user experience.

Navigating a Bulky DOM

A large DOM size can impact users in various ways:

1. Slower Load Times: The browser takes more time to parse and render a complex DOM, which can leave users staring at a blank screen longer than they'd like.
2. Increased Memory Usage: More nodes mean more memory consumption, which can be particularly taxing on mobile devices.
3. Reduced Performance: An overcrowded DOM can slow down JavaScript execution and result in laggy animations or interactions.

Compare these layout examples that contribute to DOM size. The layout on the left is far simpler than the layout on the right. If you're viewing on mobile, the first is simpler, the second more complex.

Best Practices to Keep Your DOM Size Down

Creating a streamlined DOM doesn't mean compromising on design; it's about crafting efficient code. Here are some best practices:

1. Simplify Your HTML Structure: Avoid deep nesting of elements and unnecessary wrapper divs. Each layer adds complexity and size.
2. Use CSS for Decorative Elements: Where possible, lean on CSS rather than adding extra HTML elements to achieve design complexity.
3. Batch DOM Manipulations: When manipulating the DOM with JavaScript, do so in batches rather than one node at a time. This reduces reflows and repainting.
4. Implement Lazy Loading: Only load images and other media when they’re needed. This reduces the initial DOM size and quickens load times.
5. Clean Up Your CSS and JavaScript: Redundant styles and scripts can add to your DOM size indirectly. Regularly audit and streamline your assets.

Design Practices for HubSpot CMS

When building templates and pages on HubSpot CMS, keeping your DOM lean starts with smart design practices:

• Leverage HubSpot’s Modules: Use drag-and-drop modules wisely. They help in keeping your code modular and maintainable but resist the urge to overload a page with lots of modules.
• Optimize Templates: Create templates with reusable components that adhere to a minimalistic approach. This not only reduces DOM size but also enhances consistency across pages.
• Use HubSpot’s Built-in Optimization Tools: HubSpot automatically minifies CSS/JS and optimizes images, which indirectly aids in managing DOM size.

Common Errors to Steer Clear Of

• Overusing JavaScript Frameworks: While frameworks like React and Angular are powerful, they can contribute to DOM bloat if not used judiciously.
• Unnecessary Libraries: Including entire libraries for a few features can add bloat. Opt for lightweight alternatives or custom code those features.
• Neglecting Mobile Optimization: Always design with mobile-first in mind. This encourages lighter, more efficient DOM structures.

Our Best Advice: Keep It Simple, Smarty

Websites are cluttered enough; yours doesn’t need to contribute to the chaos. By maintaining a lean DOM, you’re offering users a snappy, delightful experience while improving your site's SEO and performance. Take time to audit your website’s DOM, prune unnecessary elements, and embrace simplicity. After all, the best experiences are often the simplest.

Let's Keep It Simple, Smarty!

Now is the perfect time to evaluate your website's structure. Why not kick off with an audit today and see where you can improve? Start with the free Chrome Inspect tool. Your users—and your website metrics—will surely thank you.