Do WordPress Plugins Actually Slow Down Your Site?

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Do WordPress plugins slow down your site?

The common consensus is, “yes.”

The truth?

It depends.

In this post, I’ll dig into the specifics of how plugins affect a website’s speed so you can audit your own plugins and decide which ones to keep and which ones to delete.

Which plugins slow your site?

Here’s a rule of thumb you can apply to your site:

Plugins that change the front-end of your site slow it down. Plugins that only affect the admin dashboard do not.

We’re going to get more detailed, but if that’s your only takeaway from this post you’ll still be able to optimize your site.

Now, how about some examples?

Let’s say you install a new plugin to add social sharing buttons at the end of your posts. Does this plugin slow your site down? Yes, and you can be sure of it because it is changing the front-end of your site.

Contrarily, let’s say you add a new plugin to your site that adds categories to your Media Library. Does this slow down your site? No, because it’s only modifying the admin dashboard.

To understand this more clearly, we’ll need to uncover exactly what makes a WordPress site slower.

What exactly slows a site down?


Loading more files and bigger files is how WordPress sites get slow.

When a visitor arrives on your site, there are lots of files that get delivered from your server to their browser, and the browser’s loading indicator will spin and spin until all of the file transfers are complete.

There are three main file types that websites need to deliver to their visitors: stylesheets (CSS), Javascript (JS), and images (JPG/PNG/GIF).

CSS files are often referred to as stylesheets and they do exactly what they sound like: they style your website. All of our themes load one stylesheet that gives your site a unique design, for instance.

When you add social media buttons to your posts, they need to be styled to look nice, so the plugin has to load a stylesheet on your site, and that slows it down.

Javascript is normally used to add interactivity to a website. For example, if a visitor is reading a post and a popup form shows up, Javascript was used to make the form appear and it’s also used to hide the form when they press the “X” button.

Plugins rarely load images, but if you do see new images on your site coming from a plugin then that further increases its impact.

So here’s the conclusion we can draw from this: if a plugin adds styled content to your website then it’s loading a stylesheet, and if any part of the content is interactive, it’s also loading a Javascript file.

For the most part, no single plugin is going to slow you down that much, but the effect adds up.

If you have 20 plugins all loading a stylesheet and a Javascript file, your website’s performance is going to take a major hit. And here’s some more bad news: some plugins are really poorly optimized and load multiple stylesheets and Javascript files even though they could only load one of each. 20 plugins like this will slow your site to a crawl.

On the other hand, if you have 20 plugins installed but they only add features behind-the-scenes, then your website won’t load any slower for your visitors.

In practice, most plugins you add will affect the front-end of your site, so in general, plugins slow down your site but now you know why that is not always the case.

How to reduce plugin impact

In reading this post, you might have had this disheartening thought:

“So if I want to add social sharing buttons or any other cool feature with a plugin, it’s going to affect my site’s performance?”

Unfortunately, yes. Everything has a cost and it’s really important to know this when managing a WordPress website.

Most of the time, when someone has a really slow WordPress site it’s because they’ve been wildly installing plugins without knowing there will be a performance cost. They leave plugins active that they’re not even using anymore despite their negative impact on the site’s performance.

If that describes you, it’s okay! But it’s time to prune your plugins, and when you’re finished, I guarantee your site will load faster.

Deactivate unused plugins

This will only take a minute.

Skim your Plugins menu and find any active plugins you’re not using and deactivate them.

If a plugin is deactivated, it will not run any code or have any impact on your site’s performance whatsoever.

In general, you should also delete your deactivated plugins. The only time you should keep a deactivated plugin on your site is if you want to reuse it soon, like a maintenance mode plugin. Also, when you delete a plugin, it will delete your prior settings, so if you plan on reusing your old settings then only deactivate it.

Deleting a plugin will free up a small amount of storage space on your server but doesn’t affect how fast your site loads (deactivating it does).

Consolidate your plugins

After you deactivate the plugins you’re not using at all, you can further reduce the number of plugins you’re running by removing duplicated functionality.

I’ve seen many WordPress sites that have two plugins that do the same thing. For example, one plugin adds a social media widget while the other plugin adds social buttons after the post. These plugins can’t communicate with each other so they load their own files (2x the files). The solution? Find one plugin that can do both of these things.

When you need a feature quickly and you’re on a deadline, it’s common to install a plugin last minute just to do one little thing for your website. If you’ve got a plugin, for example, that lets you add galleries, revisit the gallery feature in WordPress and re-evaluate if you even need a plugin anymore.

Consolidating takes more time and research, but if you’ve never done this before, you can likely remove a handful of plugins and get some nice gains. Plus, your admin interface will be less cluttered when you’re done too.

Keep optimizing your site

I hope you’ve got a clear picture of how plugins impact site performance now.

You’ll see performance improvements right away after pruning your plugins, but there’s a lot more you can do to speed up your site.

I recently put together the longest blog post I’ve ever written (like in my whole life). It details every single valid method of speeding up a WordPress site I could think of.

All 36 Ways to Speed Up Your WordPress Site

I’ve used every single one of those tactics on this site and can vouch for their effectiveness. Give a few of them a shot and you might be surprised how much faster your site gets.

If you know anyone else who would appreciate this post, please share it before you go 🙂

P.S. The buttons below come from the Scriptless Social Sharing plugin which loads way faster than most other plugins (1 tiny, optional CSS file).

Ben Sibley
Ben Sibley
This article was written by Ben Sibley. He is a WordPress theme designer & developer, and founder of Compete Themes.