WordPress minify plugins

Minification is a popular way to optimize your WordPress website. There are plenty of WordPress minify plugins to help you do this, but it’s hard to know which ones provide the best results without testing them first – which can get messy.

To save you some time and effort, we decided to test a few of our top picks and provide you with the results, so you’ll know which popular minification plugins live up to their reputation.

In this article, we’ll talk about what minification is and how it can benefit your site. Then we’ll compare three of our favorite WordPress minify plugins to help you pick the best one. Let’s get started!

What minification is (and how it can benefit your site)

Minification is the process of taking a piece of code and removing all unnecessary characters from it (think white spaces, line breaks, and so on). Minified files perform exactly the same as the original code, they just take up a little less space because they cut out extraneous information.

Minification is particularly popular for scripts, stylesheets, and other similar website components. It can benefit your site by:

  • Decreasing loading times. Most modern websites use multiple scripts and stylesheets, which can combine to result in long loading times (and frustrated visitors). Minification can help speed things up.
  • Obscuring your code from casual onlookers. Minification doesn’t actually hide your site’s code, but it does make it a bit harder for casual users to interpret, if that’s something you’re worried about it. There’s no real security benefit beyond a little bit of obfuscation, though.

Minifying your code is unlikely to make a massive difference in your WordPress site’s page load times. But it is a small optimization strategy that can cut your page load times by a couple of percentage points, which makes it a worthy tactic to implement.

Three WordPress minify plugins compared

If you’d like to minify your website’s code, there are plenty of plugins that can help you out. As we mentioned at the beginning of this article, the best way to know how efficient these plugins are is to test them. To that end, we set up a test WordPress website that runs four relatively complex plugins – WooCommerce, Yoast SEO, Smush Image Compression and Optimization, and Loginizer.

Before minifying any of its scripts, our test site’s home page had a size of 311.6 KB, and it took 0.61 seconds to load (according to Pingdom Tools):

Our initial test results before using WordPress minify plugins

Throughout the next few sections, we’ll try out some top WordPress minify plugins and share our results with you. Between each test, we’ll restore our website to its initial state from a backup for accuracy’s sake. Of course, keep in mind that your own results may vary, and larger sites will likely see more significant improvements.

1. Autoptimize (Free)

Autoptimize is one of the most popular WordPress minify plugins around. Along with minifying your scripts, it can also bundle them together, cache them, and even set them to load later, in order to further optimize your website’s performance.

Testing the Autoptimize plugin

Using this particular plugin is remarkably simple. Just install and activate it, then go to the Settings → Autoptimize tab on your dashboard. Inside, you’ll find options to optimize your HTML, JavaScript, and CSS:

Autoptimize's WordPress minify plugin settings.

For this test, we enabled all three options and saved our changes. Then, we checked out our loading times:

Autoptimize's test results.

Using this plugin, we cut down our home page’s size to 297.8 KB, and our loading time decreased accordingly to 0.58 seconds. This is a small but still noticeable difference.

2. Fast Velocity Minify (Free)

Fast Velocity Minify combines your CSS and JavaScript files, so your servers have to deal with fewer requests. At the same time, it also minifies them and creates cached copies for faster loading times.

Testing the Fast Velocity Minify plugin

Unlike our previous entry, this plugin automatically enables the options to minify your HTML, JavaScript, and CSS. However, you can disable one or more of them manually by going into the Settings → Fast Velocity Minify tab:

Fast Velocity Minify's settings.

Moreover, you can exclude specific files from being minified if you’d like.

As far as performance goes, here are our results after activating this plugin and minifying all possible files:

Fast Velocity Minify's results.

Our homepage’s size came down from 311.5 to 291.3 KB, and it loaded in a mere 0.55 seconds. This is a bit better than Autoptimize’s results, although ultimately comparable.

3. Merge + Minify + Refresh (Free)

As you can imagine from its name, Merge + Minify + Refresh works its magic by combining your CSS and JavaScript files and minifying them. It also caches them so your server doesn’t have to repeat the entire loading process each time they’re requested, and it automatically updates everything when you make changes to those files.

Testing the Merge + Minify + Refresh plugin

Just like our previous pick, this plugin automatically enables minification for your JavaScript and CSS. However, it doesn’t include an option to optimize your HTML.

There are also fewer customization options here than for Fast Velocity Minify, but still more than what Autoptimize offers. For example, you can exclude files from the minification process, and even enable Gzip encoding for better results:

Merge plus Minify plus Refresh's settings.

After activating this plugin, we tested our home page’s loading times once more:

Merge plus Minify plus Refresh's results.

Our file size came down to 300.3 KB, and the page loaded in 0.58 seconds. Overall, this is a smaller improvement in overall size than we saw with the previous two plugins, but is similar to Autoptimize when it comes to performance.

A summary of our findings

Overall, the results we found during our tests were in line with our expectations. Each plugin delivered a small increase in performance, but nothing out of the ordinary:

3 top WordPress minify plugins tested and compared
AutoptimizeFast Velocity MinifyMerge + Minify + Refresh
Original page size (in KB)311.6311.6311.6
Original loading time (in seconds)0.610.610.61
Post-minification page size (in KB)297.8 (-4.43%)291.3 (-6.52%)300.3 (-3.63%)
Post-minification loading time (in seconds)0.58 (-4.92%)0.55 (-9.84%)0.58 (-4.92%)
Additional settings availableNoYesYes

The top plugin, in this case, turned out to be Fast Velocity Minify. Not only did it get the best results, but it also offers far more settings than its competitors, which makes it ideal for power users.

On the other hand, if you’re looking for an easy-to-use plugin, you can’t go wrong with Autoptimize. Its results were almost as good as Fast Velocity Minify’s, and it only requires you to enable a few settings to get going. Finally, Merge + Minify + Refresh wasn’t a disappointment when it came to results, but could benefit from including more options. Overall, it’s a decent enough middle point between the other two plugins.

Conclusion

There are plenty of choices when it comes to WordPress minify plugins, but figuring out which one is right for you can be tricky. The best way to do it is to test each of them and compare their performance. However, let’s be honest – few people have the time to do this themselves.

To make your job a little easier, we took it upon ourselves to test some of our favorite picks. Here is a recap of our results:

  1. AutoptimizeAn easy-to-use plugin that delivers decent results.
  2. Fast Velocity MinifyA tool offering solid optimization and multiple settings to help you customize your experience.
  3. Merge + Minify + RefreshA simple plugin with decent optimization results and a handful of settings.

Do you have questions about any of these WordPress minify plugins? Let’s talk about them in the comments section below!

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