{"id":804,"date":"2024-05-07T11:43:37","date_gmt":"2024-05-07T11:43:37","guid":{"rendered":"https:\/\/kb.shortpixel.com\/docs\/error-invalid-response-from-server\/"},"modified":"2025-08-27T08:42:51","modified_gmt":"2025-08-27T08:42:51","password":"","slug":"error-invalid-response-from-server","status":"publish","type":"docs","link":"https:\/\/kb.shortpixel.com\/knowledge-base\/article\/error-invalid-response-from-server\/","title":{"rendered":"Error &#8220;Invalid response from server&#8221;"},"content":{"rendered":"\n<p>The error message &#8220;Invalid response from server&#8221; can sometimes be puzzling, especially if the image actually exists and looks good in a browser.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Check the response output<\/h2>\n\n\n\n<p>If you get this error message,&nbsp;it may be that some output from another plugin (or a notice\/warning) is corrupting the JSON responses from our plugin&#8217;s AJAX calls. To see this output, do the following:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Go to Media > Bulk ShortPixel.<\/li>\n\n\n\n<li>Start optimizing your images (if you have not already).<\/li>\n\n\n\n<li>Open your browser&#8217;s developer tools (usually F12 on Windows, or Option+\u2318+&#8217; on macOS).<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/kb.shortpixel.com\/wp-content\/uploads\/2025\/08\/file-3jX3yLY2T4.png\" alt=\"\"\/><\/figure>\n\n\n\n<p>Proceed as shown in the screenshot:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Click on the <strong>Network <\/strong>tab.<\/li>\n\n\n\n<li>Select the <strong>XHR <\/strong>filter.<\/li>\n\n\n\n<li>Click on any <code>admin-ajax.php?_fs_blog_admin=true<\/code> request.<\/li>\n\n\n\n<li>Select the <strong>Response <\/strong>tab. What you see in the screenshot is the correct AJAX call.<\/li>\n<\/ol>\n\n\n\n<p>If you don&#8217;t see something similar, we recommend you to try to search for the plugin in question:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Deactivate all plugins except ShortPixel.<\/li>\n\n\n\n<li>Activate the plugins one by one. After each individual activation, try the bulk optimization again until you find the plugin that is corrupting the JSON responses.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">Check if your server is overloaded<\/h2>\n\n\n\n<p>If the above measures did not help, it&#8217;s possible that your server has&nbsp;limited capacity in terms of processing power and memory. Some of ShortPixel&#8217;s features may require more resources than others, so you may experience server overload. You can try temporarily disabling the following functions.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Convert PNG images to JPEG<\/li>\n\n\n\n<li>Optimize Retina images<\/li>\n\n\n\n<li>Optimize other thumbnails<\/li>\n<\/ul>\n\n\n\n<p>If you have a lot of thumbnails, you can try excluding some of them from optimization, as each thumbnail (and its WebP + AVIF counterpart) increases server load. You can learn how to do that in this article:<br><a href=\"https:\/\/shortpixel.com\/knowledge-base\/article\/how-can-i-optimize-only-certain-thumbnail-sizes\/\" rel=\"noopener\">How can I optimize only certain thumbnail sizes?<\/a><\/p>\n\n\n\n<p>For more information, see this article:<br><a href=\"https:\/\/shortpixel.com\/knowledge-base\/article\/my-website-seems-to-be-slower-could-this-be-because-shortpixel-is-still-optimizing-images\/\" data-type=\"docs\" data-id=\"808\" rel=\"noopener\">My website seems to be slower, could this be because of ShortPixel Image Optimizer?<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Other common problems<\/h2>\n\n\n\n<p>If you still can not figure out what&#8217;s going on, please take a look at <a href=\"https:\/\/shortpixel.com\/knowledge-base\/article\/why-some-of-the-images-and-or-thumbnails-cannot-be-optimized\/\" rel=\"noopener\">Why some of the images and\/or thumbnails cannot be optimized?<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Contact your hosting provider<\/h2>\n\n\n\n<p>As a last resort, we recommend that you\u00a0<strong>contact your hosting provider<\/strong>\u00a0to find out why our plugin cannot access your images.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The error message &#8220;Invalid response from server&#8221; can sometimes be puzzling, especially if the image actually exists and looks good in a browser. Check the response output If you get this error message,&nbsp;it may be that some output from another plugin (or a notice\/warning) is corrupting the JSON responses from our plugin&#8217;s AJAX calls. To [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","template":"","meta":{"footnotes":""},"doc_category":[37],"glossaries":[],"doc_tag":[],"class_list":["post-804","docs","type-docs","status-publish","hentry","doc_category-shortpixel-image-optimizer"],"blocksy_meta":[],"year_month":"2026-05","word_count":365,"total_views":"1107","reactions":{"happy":"0","normal":"0","sad":"0"},"author_info":{"name":"admin","author_nicename":"admin_mdli53m5","author_url":"https:\/\/kb.shortpixel.com\/author\/admin_mdli53m5\/"},"doc_category_info":[{"term_name":"ShortPixel Image Optimizer","term_url":"https:\/\/kb.shortpixel.com\/knowledge-base\/category\/shortpixel-image-optimizer\/"}],"doc_tag_info":[],"knowledge_base_info":[],"knowledge_base_slug":[],"_links":{"self":[{"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/docs\/804","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/docs"}],"about":[{"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/types\/docs"}],"author":[{"embeddable":true,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/comments?post=804"}],"version-history":[{"count":2,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/docs\/804\/revisions"}],"predecessor-version":[{"id":2459,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/docs\/804\/revisions\/2459"}],"wp:attachment":[{"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/media?parent=804"}],"wp:term":[{"taxonomy":"doc_category","embeddable":true,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/doc_category?post=804"},{"taxonomy":"glossaries","embeddable":true,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/glossaries?post=804"},{"taxonomy":"doc_tag","embeddable":true,"href":"https:\/\/kb.shortpixel.com\/wp-json\/wp\/v2\/doc_tag?post=804"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}