{"id":19031030,"date":"2026-09-28T09:24:09","date_gmt":"2026-09-28T09:24:09","guid":{"rendered":"https:\/\/wordpress.org\/support\/topic\/image-preload-causing-duplicate-downloads-on-mobile\/"},"modified":"2026-09-28T09:24:09","modified_gmt":"2026-09-28T09:24:09","slug":"image-preload-causing-duplicate-downloads-on-mobile","status":"publish","type":"topic","link":"https:\/\/wordpress.org\/support\/topic\/image-preload-causing-duplicate-downloads-on-mobile\/","title":{"rendered":"Image preload causing duplicate downloads on mobile"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">I think there is an issue with the LCP image preload.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The preload uses the image size selected in WordPress. For example if you select Large it will put the 1024 version into the preload:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;link rel=\"preload\" fetchpriority=\"high\" as=\"image\" href=\"...1024x768.png.webp\"&gt;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">But the actual image uses a responsive <code>srcset<\/code>, so on mobile it may then select a smaller image instead. This means the larger image may be downloaded first, followed by the smaller image, resulting in the image being downloaded twice on the device where we&#8217;re supposed to be minimising image sizes!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Could the preload use the same responsive image selection as the actual image, for example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;link rel=\"preload\" fetchpriority=\"high\" as=\"image\"<br \/>      imagesrcset=\"...300x225.png.webp 300w, ...768x576.png.webp 768w, ...1024x768.png.webp 1024w\"&gt;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">rather than always preloading the image size selected in WordPress?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Relevant link: <a href=\"https:\/\/html.spec.whatwg.org\/#attr-link-imagesrcset\">https:\/\/html.spec.whatwg.org\/#attr-link-imagesrcset<\/a><\/p>\n","protected":false},"template":"","class_list":["post-19031030","topic","type-topic","status-publish","hentry","topic-tag-image","topic-tag-preload"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/topic\/19031030","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/topic"}],"about":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/topic\/19031030\/revisions"}],"wp:attachment":[{"href":"https:\/\/wordpress.org\/support\/wp-json\/wp\/v2\/media?parent=19031030"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}