Wordpress LScache Plugin: WebP images not being served properly
Last Updated on: Wed, 15 Apr 2026 00:00:02 WebP images are not being served to my browser (Firefox 69). I have the following settings enabled: Optimise Automatically, Optimisation Cron, Optimise Original Images, Optimise WebP Versions, Image WebP Replacement. (WebP Attribute To Replace was left at default and WebP For Extra srcset is left at default Off) I ran LiteSpeed Cache Image Optimisation and it says All done . I have checked that webp files are available. e.g.: JPG ? https://ahbc.space/wp-content/uploads/WelcomeWillow-25-of-42.jpg WEBP ? https://ahbc.space/wp-content/uploads/WelcomeWillow-25-of-42.jpg.webp .htaccess has the correct rewriteconds/rewriterule. Chromium correctly gets served WEBP mostly (Im on Linux). On another computer Internet Explorer and Edge also get served the JPGs. The only thing I can find in the debug log (set to advanced) thats remotely relevant when loading on Firefox is: 09/20/19 10:48:04.117 [=CLI=ahbc 1 f2A] [Img_Optm] preparing images to push 09/20/19 10:48:04.124 [=CLI=ahbc 1 f2A] [Img_Optm] optimize bypass: no image found After clearing the log, and loading the site in Chromium, I get the following in the log: [Media] webp replacing: ....jpg => LSC_Media->replace_webp()@851 => LSC_Media->webp_srcset()@834 => WP_Hook->apply_filters()@288 => ... /wp-includes/media.php@208 [Media] - replaced to: ... .jpg.webp However, I also get a lot of [Util] file not exist:... .jpg.webp [Media] -no WebP file, bypassed Which seems to be on the smaller images/thumbnails sizes as opposed to the originals. Im at a loss as to why Firefox is not getting served the webp images and Chromium is only some. The page I need help with: https://ahbc.space Hi @thorned-rose, According to Mozilla org, Firefox has removed image/webp on http_accept header since version 66, so our source code and .htaccess file do not support webp replacement on Firefox browser. Currently, we do not have a safe way to detect are the users FF browser supporting Webp because the user can turn it off on about:config settings tab. but if you wish to force serving Webp on version >65 Firefox, you can try to update the following code: You need to update the .htaccess file as: https://www.diffchecker.com/fAPSFT81 and the media.class.php plugins/litespeed-cache/inc/media.class.php as: https://www.diffchecker.com/TJC5h3Rq Thanks.
LiteCache Rush: Speed comes from using less, not from doing it faster
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