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Improve your website performance with Minify and W3 Total Cache Pro.

Frequently Asked Questions

What can I do to speed up the delivery of static assets?

HTTP/2 push – can be enabled to send assets contents right with the HTML content which speeds up rendering time.

How can I eliminate render blocking CSS?

W3 Total Cache can help with that by embedding CSS assets included an external asset to HTML. The only drawback is that CSS is sent on each page visit, so naturally it is not taken from browser cache.  so you get faster page rendering for the 1st visit and slower for subsequent visits. This is only suggested when website has a small amount of CSS, otherwise it’s better to use HTTP/2 pushing.

What can I do about external scripts and stylesheets?

Fine-tuning – you can add your external assets to minified assets to avoid multiple DNS resolution and connection handshakes.

How can I eliminate render blocking Javascript?

Eliminating render blocking JS files is the same thing as deferring them. When a javascript file is deferred, it is not executed right at the HTML page parsing point of time, but after the page is initially rendered and the visitor has began reading the content.

Our team provides this as a Premium Service, but in some simple cases may be solved via Minify Manual mode without coding. You can select the scripts you want to change, their placement and order, and the way they are included (async/defer).

How can I Reduce Unused JavaScript and CSS?

Lighthouse and Google PageSpeed Insights may advise you to Reduce Unused JavaScript or to Reduce Unused CSS. This can be one of the most difficult recommendations to follow, for a few reasons.

First, the recommendation engine itself is pretty simple. Take this example of pseudo-code:

if ( is_page('home') ) {
   /* A chunk of code that only displays on the homepage */
} else {
   /* A chunk of code that displays on all other pages */

In this example, if you were to run PageSpeed Insights on your home page, everything in the code block that displays on all your other pages counts as “unused.” Because of this, you should keep in mind that the “unused” measurements aren’t always a completely accurate measurement. Similarly, if your CSS includes rules for elements that only appear on certain pages, that will also show up as “unused” even though you may be using those CSS rules on other pages of your website.

The most effective way to remove unused JavaScript and CSS is to remove any extraneous plugins that you may have on your website. In addition, make sure that the plugins you do choose to use only enqueue their assets on pages that use those plugins.However, W3 Total Cache also offers another tool for your to mitigate unused assets.

Including Assets only on Certain Templates

Using Manual Minify, you have the ability to only include JavaScript and CSS Assets on certain theme templates. You can utilize this feature to create templates within your theme that need additional assets. For example, if you have a Contact Form, you can create a unique contact form template and include your form plugin’s assets only on that template.

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18 thoughts on “W3 Total Cache Minify FAQ

    • Hello Sasa,

      Thank you for reaching out.
      I’ve checked your website and I can see that the main problem is the images and the render-blocking files. Since you are using Autoptimize, you should use that plugin to eliminate render-blocking files or disable that plugin and use the W3 Total Cache Minify option. You should not use both W3TC and Autoptimize to minify at the same time so you should choose only one plugin for this. We of course recommend you try the W3 Total Cache.
      You can convert the images to webp with the W3 Total Cache Image service extension in Performance>Extension to serve the next-gen webp images.
      I hope this helps!

  1. hallo all ,
    after i install the Plugin the pices on Mobile Version disabeard , i tried to go back and uncheckd the option but doesnt the pices on fron page on Mobile are disabeard, but when i click on any actogery i see the pices , that mean the issue only by front page ? Need help to solve this issue

      • Dear Marko,

        I seriously need your help. After installing the W3 total cache plugin, many pages of our website: got broken. Is there any option to redo the changes? Please help me to fix this problem.

        Many thanks and I’ll be looking forward to hearing from you soon.

        Best Regards,


        • Hi Romany.

          Can you please disable minify in Perfirmance>General settings, save all settings and purge the cache and see if the issue persists?
          If the issue is gone, re-enable minify, and disable the settings in Performance>minify one by one (HTML minify, JS minify, CSS minify) and see which one might be causing the issue.
          Make sure to save all settings and purge the cache after each option is disabled.
          If you’d like us to take a look for you, please let us know in the Support Forums or via the plugin in Performance>Support.

  2. I having a issue about mobile responsiveness after intalling W3 total cache plugin. It seems the mobile’s CSS is not being reading.

    I’m using gulp (css minify plugin) and I would like to know if is possible to disable the W3 Total Cache’s CSS minify feature instead.

    • Hello Renan-

      Yes, you can disable CSS Minify. In the Performance > Minify > CSS menu, look for the checkbox at the top and ensure that it is unchecked. Save the changes and clear your cache, and you should no longer see W3 Total Cache’s minified CSS.

      • Thanks for the help but, It didn’t solved my problem. Unfortunately I still have the same issue and the website got very slow.
        Thanks anyway.

    • Hi Rafa-
      Thanks for the comment, I’m sorry to hear you weren’t able to achieve the scores you needed. Every site is unique when it comes to minification, so if you’d like us to take a look for you, please let us know in the Support Forums and we’ll be happy to help.

  3. Hello,
    i have a question about the best settings for google pagespeed rating.
    for example
    google search results on speed are still nog good enough. the pagespeed score voor desktop is 91 but for mobile it is 50.
    when i look at lighthouse treemap is see wp-content/cache/minify has a lot of unused bytes.
    i tried serval options in the minify settings screen, but ratings stay’s arround 50.

    • Hi Jeroen-

      Thanks for the great question. I’ve updated the article above to include some more information about “Reducing Unused JavaScript/CSS.”

      This can be one of the trickier recommendations to follow, because the measurement can be misleading. However, the best way to eliminate unused JavaScript and CSS is to make sure that you don’t have any active plugins that you aren’t actively using.

      You can also utilize the Template option in the Manual Minify settings to make sure that your JS and CSS assets are only included on certain theme templates, so that the assets don’t go unused on pages that don’t utilize the feature.

    • Hello David-

      The developers do strive to keep the various Minify Libraries in W3 Total cache as current as possible, you’re right that it may interfere with other minification solutions like Autoptimize and WP-Optimize. You should only use one minification solution to avoid issues with library conflicts and minifying code with two different algorithms at once.

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