When you visit a website, your browser has to download, read, and run every single file to display the page. But sometimes, a website downloads a lot of extra code that it doesn’t even need. This is called unused JavaScript, and it’s a big problem for your website’s performance.
Unused JavaScript can slow down your page load time and make your website feel sluggish. It’s a bit like having a car with a trunk full of junk. The car still works, but it’s much slower and less efficient. This has a huge negative impact on your user experience and your SEO.
Why You Should Remove Unused JavaScript
Removing unused JavaScript isn’t just about making your website faster. It’s about making your website better for your users and for search engines.
It Hurts Pagespeed
When a browser loads a page, it has to stop and process every JavaScript file. If those files contain a lot of unused code, the browser is wasting time and resources on something it doesn’t need. This can significantly delay the time it takes for your page to become interactive, which is a key metric for a good user experience.
It Damages Your SEO
Your pagespeed is a direct ranking factor. A website with a lot of unused JavaScript will be slower, and a slower website will rank lower than a faster one. Unused JavaScript also affects key performance metrics like First Input Delay (FID), which measures how long it takes for a browser to respond to a user’s first interaction. A low FID score is a signal to search engines that your website is high-quality.
How to Find Unused JavaScript on Your Site
So, how do you find all this extra code? There are a few different ways to find unused JavaScript on your website:
- Browser Developer Tools: The Coverage tab in your browser’s developer tools can show you exactly which lines of code are being used and which are not.
- Pagespeed Audits: A pagespeed audit tool will flag unused JavaScript and other performance issues.
- Professional SEO Platforms: A professional SEO platform like Clickrank can scan your entire website and give you a prioritized list of tasks to fix these issues. This allows you to focus on your content and other SEO tasks while the platform takes care of the technical side.
How to Reduce or Remove Unused JavaScript
Minify Your Code
Minifying your code is a simple way to remove unused JavaScript. It involves removing all the extra spaces and characters from your code without changing its functionality. This is a task that a developer can automate as part of their workflow.
Remove Unused Libraries
Sometimes, a website will load a JavaScript library that is only used on a few pages. If you can, you should only load that library on the pages that actually need it. If a library is not used on any page, you should remove it completely.
Defer Loading
Deferring the loading of a JavaScript file means that you are telling the browser to load it after the page has been displayed. This is a great way to improve your pagespeed, as it allows the browser to display the most important content first. You can defer the loading of a JavaScript file by adding a defer attribute to the script tag.
Use the Right Plugins
If you are using a CMS like WordPress, you should be careful about which plugins you use. Many plugins load extra JavaScript that is not used on every page. You should only use essential plugins for your website’s functionality, such as the ClickRank WordPress plugin, which is lightweight and SEO-friendly.
