Title: Minify CSS file
Last modified: February 3, 2025

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# Minify CSS file

 *  [cfm168](https://wordpress.org/support/users/cfm168/)
 * (@cfm168)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/)
 * Hello,
 * I’m using a SEO plugin and get a list of CSS files need to be minified. Can enabled“
   Aggregate CSS-files” will minify those CSS files? If not, please advise how to
   minify all css files.
 * Thanks in advance!

Viewing 9 replies - 1 through 9 (of 9 total)

 *  Thread Starter [cfm168](https://wordpress.org/support/users/cfm168/)
 * (@cfm168)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18283172)
 * And also how to set to minify JavaScript files? The SEO program showing a list
   of JavaScript files still need to be minified.
 *  Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/)
 * (@optimizingmatters)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18283254)
 * if the files are local (as opposed to 3rd party CSS/ JS) and if the filenames
   indicate they are not minified (e.g. jquery.min.js is considered minified, jquery.
   js is not considered minified) then activating “optimize CSS” and “optimize JS”
   will indeed minify local non-minified files.
 * hopes this clarifies,
    frank
 *  Thread Starter [cfm168](https://wordpress.org/support/users/cfm168/)
 * (@cfm168)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18285620)
 * I already activated those two features “optimize CSS” and “optimize JS”.
 * These two files are not minified:
   wp-includes/js/thickbox/thickbox.csswp-includes/
   js/thickbox/thickbox.js
 * And other non minified files are related to Plugin.
 * Please advise how to minify them. Thanks!
 *  Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/)
 * (@optimizingmatters)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18285737)
 * you’ll likely have `wp-includes/js` in the JS optimization exclusion list, try
   removing it there but make sure to test if everything still works.
 *  Thread Starter [cfm168](https://wordpress.org/support/users/cfm168/)
 * (@cfm168)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18287189)
 * No, the exclusion list on JS and CSS are empty.
 * Can I delete all cache in wp-content/cache/autoptimize/?
 *  Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/)
 * (@optimizingmatters)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18287218)
 * > No, the exclusion list on JS and CSS are empty.
 * in that case toggle the “compatibility logic” near the bottom of the main settings
   page.
 * > Can I delete all cache in wp-content/cache/autoptimize/?
 * sure you can, but make sure to also clear any page cache(s) you might have 🙂
 *  Thread Starter [cfm168](https://wordpress.org/support/users/cfm168/)
 * (@cfm168)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18287259)
 * If enable “Disable extra compatibility logic?”, is it possible causes site down?
   Do I need to back up the site first?
 *  Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/)
 * (@optimizingmatters)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18287272)
 * the compatibility logic aims to prevent things breaking, so it is certainly possible
   that you need that compatibility logic to prevent issues, in which case you’ll
   have to live with those 2 files not being minified.
 *  Thread Starter [cfm168](https://wordpress.org/support/users/cfm168/)
 * (@cfm168)
 * [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18287394)
 * Just checked the “Disable extra compatibility logic?”. It seems the site get 
   a bit faster browsing.
 * I will update here again about minify a week later. Thank you!

Viewing 9 replies - 1 through 9 (of 9 total)

The topic ‘Minify CSS file’ is closed to new replies.

 * ![](https://ps.w.org/autoptimize/assets/icon-256X256.png?rev=2211608)
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 * 9 replies
 * 2 participants
 * Last reply from: [cfm168](https://wordpress.org/support/users/cfm168/)
 * Last activity: [1 year, 4 months ago](https://wordpress.org/support/topic/minify-css-file/#post-18287394)
 * Status: not resolved