WPML slows down site drastically

This thread is resolved. Here is a description of the problem and solution.

Problem:
The client reported significant slowdowns on their website when WPML was enabled, despite having a high-performance server setup. The site performed well without WPML and with fewer active plugins, but slowed down considerably when more plugins were activated alongside WPML.

Solution:
We conducted a series of tests to isolate the issue, including updating themes, minimal plugin activation, and detailed performance monitoring. It was determined that the performance issue was not caused by WPML itself but by a third-party plugin, specifically 'Ultimate GDPR & CCPA'. This plugin was found to consume a significant amount of runtime due to a function running a regex callback on numerous posts, which severely impacted site performance. We recommended deactivating this plugin or contacting its support for a resolution.

If this solution does not resolve your issue, or if it seems outdated or irrelevant to your case, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If problems persist, please open a new support ticket at WPML support forum for further assistance.

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Tagged: Performance

This topic contains 21 replies, has 1 voice.

Last updated by Carlos Rojas 2 months ago.

Assisted by: Carlos Rojas.

Author	Posts
August 6, 2025 at 11:59 am #17299318
Carlos Rojas WPML Supporter since 03/2017 Languages: English (English ) Spanish (Español ) Timezone: Europe/Madrid (GMT+02:00)	Do you authorize me to create a copy of the site to escalate this ticket to our 2nd tier of support?
August 6, 2025 at 12:04 pm #17299332
marlonF	sure. You are hereby authorized to copy the site. I also have an ongoing fiverr gig for someone who tries to fix it on another staging version. He also can't manage to figure out the culprit.
August 6, 2025 at 12:23 pm #17299437
Carlos Rojas WPML Supporter since 03/2017 Languages: English (English ) Spanish (Español ) Timezone: Europe/Madrid (GMT+02:00)	Thank you for your authorization. I have escalated this ticket to our 2nd tier of support and asked them to take a deeper look. I will get back to you as soon as I get more information.
August 12, 2025 at 9:32 am #17312626
Carlos Rojas WPML Supporter since 03/2017 Languages: English (English ) Spanish (Español ) Timezone: Europe/Madrid (GMT+02:00)	Hi there, Our 2nd tier specialists investigated the site, and they found a plugin that takes 82.9% of the run time in a function \CT_Ultimate_GDPR_Controller_Cookie::fix_content in /wp-content/plugins/ct-ultimate-gdpr/includes/controller/controller-cookie.php The request is running a regex callback that goes over quite some posts - about 155-156 posts. Each of those consumes 0.6% (top) to 0.5(minimum) of the load time, and this is done on the PHP output buffer, which is always a bad idea. Plugin Name: Ultimate GDPR & CCPA Please deactivate this plugin o contact their support service, and ask them to check the mentioned function.
August 12, 2025 at 6:48 pm #17314890
Carlos Rojas WPML Supporter since 03/2017 Languages: English (English ) Spanish (Español ) Timezone: Europe/Madrid (GMT+02:00)	Hello again, Our specialists have thoroughly investigated the issue and, after running all necessary tests, we have confirmed that the cause is not related to the WPML plugins. The performance problem appears to be coming from the third-party plugin you are using. Since it is a paid plugin from CodeCanyon, we recommend contacting the plugin’s author for assistance. They will be best placed to address and resolve the issue, as it is unrelated to WPML compatibility.
August 13, 2025 at 6:51 am #17315586
marlonF	Wow. Thank you so much, this was really hard to troubleshoot for me as it worked fine when just the GDPR plugin and WPML was activated. And the more and more plugins were activated the regex you talked about hit more and more and drained server ressources.
August 13, 2025 at 7:13 am #17315709
Carlos Rojas WPML Supporter since 03/2017 Languages: English (English ) Spanish (Español ) Timezone: Europe/Madrid (GMT+02:00)	Great! Please don't hesitate to contact us if you need our help in the future with WPML. We are here to help. Have an excellent day!