{"id":14390,"date":"2025-07-29T05:25:41","date_gmt":"2025-07-29T05:25:41","guid":{"rendered":"https:\/\/www.24x7wpsupport.com\/blog\/?p=14390"},"modified":"2025-08-06T05:27:52","modified_gmt":"2025-08-06T05:27:52","slug":"how-to-fix-wordpress-admin-ajax-php-400-bad-request-error","status":"publish","type":"post","link":"https:\/\/www.24x7wpsupport.com\/blog\/how-to-fix-wordpress-admin-ajax-php-400-bad-request-error\/","title":{"rendered":"How to Fix WordPress admin-ajax.php 400 Bad Request Error"},"content":{"rendered":"<div class=\"wpb-content-wrapper\"><p class=\"last-updated\">Last updated on August 6th, 2025 at 05:27 am<\/p><p>[vc_row][vc_column][vc_empty_space][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Introduction&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]If you run a WordPress website, you may have seen strange errors. The admin-ajax.php 400 Bad Request error is among the most annoying issues WordPress users encounter. It often appears without warning and can break key features of your site. Forms stop working, buttons do nothing, and even your theme might act strangely.<\/p>\n<p>This error is tied to something called <strong>AJAX<\/strong>. AJAX allows parts of your website to update without reloading the page. WordPress uses this for things like contact forms, live search, and background tasks. The file admin-ajax.php handles these AJAX requests.<\/p>\n<p>When something goes wrong with an AJAX request, WordPress may return a <strong>400 Bad Request<\/strong> error. This means the server thinks the request is invalid or broken. While it sounds simple, fixing this error can be tricky. The cause might be in your code, a plugin, or even your browser.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Why This Error Matters&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]You may wonder why one small file causes so many problems. The reason is that admin-ajax.php is used everywhere in WordPress. Many popular plugins and themes depend on it.<\/p>\n<p>When this error shows up:<\/p>\n<ul>\n<li>AJAX forms may not submit<\/li>\n<li>Plugins might stop working<\/li>\n<li>Some admin actions fail silently<\/li>\n<li>User experience drops quickly<\/li>\n<\/ul>\n<p>If your site depends on dynamic features, this can lead to lost visitors or sales.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;What is admin-ajax.php in WordPress&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]In WordPress, many actions happen without reloading the page. Think of submitting a form, liking a post, or loading more content. AJAX, which stands for Asynchronous JavaScript and XML, is used in these features.<\/p>\n<p>WordPress handles these AJAX requests through a special file called <strong>admin-ajax.php<\/strong>. This file is found in the \/wp-admin\/ folder of every WordPress site. It works in both the backend (admin area) and the frontend (user-facing side).<\/p>\n<p>When your site needs to fetch or send data without reloading, it sends a request to this file. The file then tells WordPress how to handle the task.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Why admin-ajax.php Is So Important&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]This file is like a traffic controller for AJAX tasks. It handles every request and directs it to the correct function in your theme or plugin.<\/p>\n<p>Here are some common features that use it:<\/p>\n<ul>\n<li>Contact forms<\/li>\n<li>Live search bars<\/li>\n<li>&#8220;Load more&#8221; buttons<\/li>\n<li>WooCommerce add-to-cart buttons<\/li>\n<li>Auto-save in the post editor<\/li>\n<\/ul>\n<p>Without admin-ajax.php, many of these would stop working.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;How It Works Behind the Scenes&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]Every AJAX request sent to WordPress must call admin-ajax.php. It also needs to include a parameter called <strong>&#8220;action&#8221;<\/strong>. This tells WordPress which function to run.<\/p>\n<p>For example, a form might send this:<\/p>\n<p>\/wp-admin\/admin-ajax.php?action=submit_form<\/p>\n<p>Then WordPress looks for a function linked to &#8216;submit_form&#8217;.<\/p>\n<p>There are two types of AJAX hooks used:<\/p>\n<ul>\n<li>wp_ajax_{action} \u2013 for <strong>logged-in users<\/strong><\/li>\n<li>wp_ajax_nopriv_{action} \u2013 for <strong>logged-out users<\/strong><\/li>\n<\/ul>\n<p>If you use the wrong hook, the request can fail. That\u2019s when you might see the <strong>admin-ajax.php 400 Bad Request<\/strong> error.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;What Causes a 400 Bad Request in admin-ajax.php&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]The admin-ajax.php 400 Bad Request error happens when WordPress receives a broken or incomplete request. This typically indicates that there is a problem with the way AJAX is sending data to the server. This can happen for a variety of reasons, and the first step in resolving it is determining the precise cause.<\/p>\n<p>Let&#8217;s take a closer look at the most frequent reasons.<\/p>\n<ol>\n<li><strong> Malformed AJAX Request<\/strong><\/li>\n<\/ol>\n<p>A malformed AJAX request is built incorrectly. When a script sends data to the server, it must follow a proper format. The server might not understand if something is missing or not in its proper place.<\/p>\n<p>For example, if a plugin sends an AJAX request with missing or improperly formatted parameters, WordPress might return a 400 error.<\/p>\n<p>Malformed requests may be caused by:<\/p>\n<ul>\n<li>JavaScript bugs in your theme or plugin<\/li>\n<li>Using incorrect syntax when building the request<\/li>\n<li>Encoding errors in the data payload<\/li>\n<\/ul>\n<p>This issue often arises during custom development or when using outdated plugins.<\/p>\n<ol start=\"2\">\n<li><strong> Missing Action Parameter<\/strong><\/li>\n<\/ol>\n<p>Every request in WordPress AJAX needs to contain a &#8220;action&#8221; parameter. This tells WordPress which function to run on the server side.<\/p>\n<p>If the action parameter is missing, empty, or misspelled, WordPress won\u2019t know what to do with the request. Consequently, a 400 Bad Request error is returned.<\/p>\n<p>For instance, a request like this:<\/p>\n<p style=\"padding-left: 30px;\">jQuery.post(ajaxurl, { name: &#8216;John&#8217; });<\/p>\n<p>Will fail because it lacks the required action field. The correct version should look like:<\/p>\n<p style=\"padding-left: 30px;\">jQuery.post(ajaxurl, { action: &#8216;my_custom_function&#8217;, name: &#8216;John&#8217; });<\/p>\n<p>Even a small typo in the action name can break the request.<\/p>\n<ol start=\"3\">\n<li><strong> Incorrect AJAX URL<\/strong><\/li>\n<\/ol>\n<p>The target URL for all AJAX calls in WordPress should be:<\/p>\n<p>\/wp-admin\/admin-ajax.php<\/p>\n<p>If this URL is hardcoded incorrectly, or if a plugin points the request to another location, the server won\u2019t recognize the call. This can result in a 400 error.<\/p>\n<p>Some common causes:<\/p>\n<ul>\n<li>Manually editing AJAX URLs in JavaScript<\/li>\n<li>Using incorrect ajaxurl in the frontend<\/li>\n<li>CDN or caching plugins modifying the URL<\/li>\n<\/ul>\n<p>Always use admin_url(&#8216;admin-ajax.php&#8217;) in PHP or the global ajaxurl variable in JavaScript to ensure the correct path is used.<\/p>\n<ol start=\"4\">\n<li><strong> wp_ajax vs wp_ajax_nopriv Hook Misuse<\/strong><\/li>\n<\/ol>\n<p>WordPress provides two types of AJAX hooks:<\/p>\n<ul>\n<li>wp_ajax_{action} \u2013 For logged-in users<\/li>\n<li>wp_ajax_nopriv_{action} \u2013 For non-logged-in users<\/li>\n<\/ul>\n<p>If your site only uses one of these and not the other, your AJAX request may fail depending on who sends it.<\/p>\n<p>For example, if a visitor (logged out) clicks a button that sends an AJAX request, and you\u2019ve only set up wp_ajax_{action}, WordPress won\u2019t respond correctly. This mismatch leads to a 400 error.<\/p>\n<p>Developers often forget to register both hooks when creating public-facing features.<\/p>\n<ol start=\"5\">\n<li><strong> Plugin or Theme Conflicts<\/strong><\/li>\n<\/ol>\n<p>Sometimes a plugin or theme tries to run an AJAX call that another plugin or the theme itself is also handling. This can lead to unexpected results.<\/p>\n<p>Conflicts can happen when:<\/p>\n<ul>\n<li>Multiple plugins register the same AJAX action name<\/li>\n<li>Scripts send different data structures to the same action<\/li>\n<li>JavaScript is outdated or loaded in the wrong order<\/li>\n<\/ul>\n<p>These conflicts often produce broken requests, leading to the 400 error. Debugging tools like your browser\u2019s developer console can help detect where the request is going wrong.<\/p>\n<ol start=\"6\">\n<li><strong> Large File Uploads via AJAX<\/strong><\/li>\n<\/ol>\n<p>Uploading files through AJAX works well \u2014 until the files get too big.<\/p>\n<p>WordPress and your server both have limits on how large a file can be. If your AJAX request tries to send a file that exceeds these limits, the server may reject it.<\/p>\n<p>Key PHP settings that affect this include:<\/p>\n<ul>\n<li>upload_max_filesize<\/li>\n<li>post_max_size<\/li>\n<li>max_input_vars<\/li>\n<\/ul>\n<p>When the data is too large, the server fails to process the request and returns a 400 Bad Request.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Step-by-Step Fixes (Core Troubleshooting Guide)&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]Now that you know the possible causes of the <strong>admin-ajax.php 400 Bad Request<\/strong> error, it&#8217;s time to fix it. In this section, we\u2019ll walk through each fix in a simple, clear way. To follow these procedures, you don&#8217;t have to be a developer.<\/p>\n<p>Let\u2019s get started.<\/p>\n<ol>\n<li><strong> Clear Browser Cache and Cookies<\/strong><\/li>\n<\/ol>\n<p>Your browser may occasionally save outdated information that conflicts with AJAX queries. A quick and simple solution is to clear the cache and cookies.<\/p>\n<p><strong>Steps to clear browser cache:<\/strong><\/p>\n<ul>\n<li>Open your browser (Chrome, Firefox, or Safari)<\/li>\n<li>Press <strong>Ctrl + Shift + Delete<\/strong> (or <strong>Cmd + Shift + Delete<\/strong> on Mac)<\/li>\n<li>Choose <strong>&#8220;All time&#8221;<\/strong> for the time range<\/li>\n<li>Check the boxes for <strong>&#8220;Cached images and files&#8221;<\/strong> and <strong>&#8220;Cookies&#8221;<\/strong><\/li>\n<li>Click <strong>Clear Data<\/strong><\/li>\n<\/ul>\n<p>After clearing, reload your WordPress site and try again. If you recently upgraded plugins or made script modifications, this repair is quite helpful.<\/p>\n<ol start=\"2\">\n<li><strong> Check for Incorrect AJAX URL<\/strong><\/li>\n<\/ol>\n<p>AJAX requests must be sent to the correct URL. In WordPress, this should be:<\/p>\n<p style=\"padding-left: 30px;\">\/wp-admin\/admin-ajax.php<\/p>\n<p>Using the wrong URL will trigger a 400 error. This is common when developers hardcode the URL instead of using WordPress functions.<\/p>\n<p><strong>How to fix:<\/strong><\/p>\n<ul>\n<li>In your JavaScript code, always use the ajaxurl variable<\/li>\n<li>In PHP, use admin_url(&#8216;admin-ajax.php&#8217;) to get the correct path<\/li>\n<li>Avoid typing the full URL manually<\/li>\n<\/ul>\n<p><strong>Example (JavaScript):<\/strong><\/p>\n<p style=\"padding-left: 30px;\">jQuery.post(ajaxurl, {<\/p>\n<p style=\"padding-left: 30px;\">\u00a0\u00a0action: &#8216;my_function&#8217;,<\/p>\n<p style=\"padding-left: 30px;\">\u00a0\u00a0data: &#8216;example&#8217;<\/p>\n<p style=\"padding-left: 30px;\">});<\/p>\n<p>This ensures the request always goes to the right place, even if your domain or site path changes.<\/p>\n<ol start=\"3\">\n<li><strong> Use Developer Tools to Inspect AJAX Requests<\/strong><\/li>\n<\/ol>\n<p>Most modern browsers have tools to inspect AJAX activity. These tools can show exactly what data is being sent and returned.<\/p>\n<p><strong>Steps using Chrome DevTools:<\/strong><\/p>\n<ul>\n<li>Open your site in Chrome<\/li>\n<li>Press <strong>F12<\/strong> to open Developer Tools<\/li>\n<li>Click the <strong>&#8220;Network&#8221;<\/strong> tab<\/li>\n<li>Filter by <strong>&#8220;XHR&#8221;<\/strong> to see AJAX requests<\/li>\n<li>Click on the failing request<\/li>\n<li>Check the <strong>Headers<\/strong>, <strong>Payload<\/strong>, and <strong>Response<\/strong> tabs<\/li>\n<\/ul>\n<p>Look for signs like:<\/p>\n<ul>\n<li>Missing action name<\/li>\n<li>Incorrect content-type (e.g., not JSON)<\/li>\n<li>Response message saying \u201cBad Request\u201d<\/li>\n<\/ul>\n<p>This helps pinpoint whether the problem is in the request or response.<\/p>\n<ol start=\"4\">\n<li><strong> Add the Missing Action Parameter<\/strong><\/li>\n<\/ol>\n<p>Every AJAX request must include an <strong>action<\/strong>. This tells WordPress which function to run.<\/p>\n<p><strong>What to check:<\/strong><\/p>\n<ul>\n<li>Make sure action is included in your request<\/li>\n<li>Ensure the action name matches the one used in your functions.php or plugin file<\/li>\n<li>Double-check spelling and case (it\u2019s case-sensitive)<\/li>\n<\/ul>\n<p><strong>Example (Correct):<\/strong><\/p>\n<p style=\"padding-left: 30px;\">jQuery.post(ajaxurl, {<\/p>\n<p style=\"padding-left: 30px;\">\u00a0\u00a0action: &#8216;submit_contact_form&#8217;,<\/p>\n<p style=\"padding-left: 30px;\">\u00a0\u00a0name: &#8216;John&#8217;<\/p>\n<p style=\"padding-left: 30px;\">});<\/p>\n<p>If this parameter is missing, WordPress doesn\u2019t know which function to trigger, and a 400 error will occur.<\/p>\n<ol start=\"5\">\n<li><strong> Fix Hook Usage: wp_ajax vs wp_ajax_nopriv<\/strong><\/li>\n<\/ol>\n<p>In WordPress, there are two types of AJAX hooks:<\/p>\n<ul>\n<li>wp_ajax_{action} \u2013 for logged-in users<\/li>\n<li>wp_ajax_nopriv_{action} \u2013 for logged-out visitors<\/li>\n<\/ul>\n<p>If you&#8217;re building a public-facing feature (like a contact form), and only use wp_ajax_{action}, visitors will get a 400 error.<\/p>\n<p><strong>How to register both hooks:<\/strong><\/p>\n<p style=\"padding-left: 30px;\">add_action(&#8216;wp_ajax_submit_contact_form&#8217;, &#8216;handle_contact_form&#8217;);<\/p>\n<p style=\"padding-left: 30px;\">add_action(&#8216;wp_ajax_nopriv_submit_contact_form&#8217;, &#8216;handle_contact_form&#8217;);<\/p>\n<p style=\"padding-left: 30px;\">This makes sure the function runs no matter who sends the request.<\/p>\n<ol start=\"6\">\n<li><strong> Deactivate Plugins to Check for Conflicts<\/strong><\/li>\n<\/ol>\n<p>A plugin may be sending broken AJAX requests or interfering with the action hooks.<\/p>\n<p><strong>How to test:<\/strong><\/p>\n<ul>\n<li>Go to your WordPress dashboard<\/li>\n<li>Navigate to <strong>Plugins &gt; Installed Plugins<\/strong><\/li>\n<li>Deactivate all plugins<\/li>\n<li>Test the AJAX feature again<\/li>\n<\/ul>\n<p>If the error disappears, one of your plugins is the problem. One by one, reactivate each plugin while testing.<\/p>\n<p>Once the error returns, you\u2019ll know which plugin is causing the issue.<\/p>\n<p><strong>Tip:<\/strong> Use a staging site or enable &#8220;Troubleshooting Mode&#8221; with the <strong>Health Check &amp; Troubleshooting plugin<\/strong> to avoid breaking the live site.<\/p>\n<ol start=\"7\">\n<li><strong> Fix Large File Upload Settings<\/strong><\/li>\n<\/ol>\n<p>If your AJAX request involves uploading a file, make sure your server can handle the size.<\/p>\n<p><strong>Common issues:<\/strong><\/p>\n<ul>\n<li>File exceeds upload size limits<\/li>\n<li>Server blocks large POST requests<\/li>\n<li>Timeout due to slow connection<\/li>\n<\/ul>\n<p><strong>How to check and fix (via php.ini or .htaccess):<\/strong><\/p>\n<ul>\n<li>upload_max_filesize = 64M<\/li>\n<li>post_max_size = 64M<\/li>\n<li>max_input_time = 300<\/li>\n<li>max_execution_time = 300<\/li>\n<\/ul>\n<p>After increasing these values, restart your server or contact your hosting provider for help. Also make sure your plugin or theme doesn&#8217;t have additional limits set in its code.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Best Practices to Avoid admin-ajax.php 400 Errors&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]Fixing the error is important, but preventing it is even better. The likelihood of encountering the admin-ajax.php 400 Bad Request problem again can be decreased by adhering to a few best practices.<\/p>\n<p>Here are a few easy yet efficient ways to maintain an error-free website.<\/p>\n<ol>\n<li><strong> Always Use the Correct AJAX URL<\/strong><\/li>\n<\/ol>\n<p>Never hardcode the admin-ajax URL. WordPress provides safe and flexible ways to call it.<\/p>\n<p><strong>Use this in PHP:<\/strong><\/p>\n<p style=\"padding-left: 30px;\">echo admin_url(&#8216;admin-ajax.php&#8217;);<\/p>\n<p><strong>Use this in JavaScript:<br \/>\n<\/strong>\u00a0Use the ajaxurl variable that WordPress defines for you.<\/p>\n<p>This ensures the request goes to the correct file, even if your site URL changes.<\/p>\n<ol start=\"2\">\n<li><strong> Use Both wp_ajax and wp_ajax_nopriv Hooks<\/strong><\/li>\n<\/ol>\n<p>Make sure to register AJAX actions for both logged-in and logged-out users. Forgetting one can break your feature for some users.<\/p>\n<p><strong>Example:<\/strong><\/p>\n<p style=\"padding-left: 30px;\">add_action(&#8216;wp_ajax_my_action&#8217;, &#8216;my_function&#8217;);<\/p>\n<p style=\"padding-left: 30px;\">add_action(&#8216;wp_ajax_nopriv_my_action&#8217;, &#8216;my_function&#8217;);<\/p>\n<p style=\"padding-left: 30px;\">This handles requests from everyone.<\/p>\n<ol start=\"3\">\n<li><strong> Validate and Sanitize Input Data<\/strong><\/li>\n<\/ol>\n<p>Always check and clean the data you receive in your functions. This prevents malformed requests and protects your site from attacks.<\/p>\n<p>Use WordPress functions like:<\/p>\n<ul>\n<li>sanitize_text_field()<\/li>\n<li>esc_html()<\/li>\n<li>check_ajax_referer()<\/li>\n<\/ul>\n<p>These functions ensure the request is safe and complete.<\/p>\n<ol start=\"4\">\n<li><strong> Keep Your Plugins and Themes Updated<\/strong><\/li>\n<\/ol>\n<p>AJAX problems might be caused by issues in outdated plugins or themes. Always update them to the latest versions. This includes:<\/p>\n<ul>\n<li>WordPress core<\/li>\n<li>Active plugins<\/li>\n<li>Your theme and child theme<\/li>\n<\/ul>\n<p>Updates often include security fixes and improved compatibility.<\/p>\n<ol start=\"5\">\n<li><strong> Test New Features on a Staging Site<\/strong><\/li>\n<\/ol>\n<p>Avoid testing new code or plugins on your live website. For early error detection, use a staging environment.<\/p>\n<p>This keeps your live site stable and error-free.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Conclusion&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]Handling WordPress errors can be stressful, especially when they break important features. You shouldn&#8217;t have to spend hours debugging confusing AJAX issues alone. If you&#8217;re still facing problems or want to make sure your site is running smoothly, expert help is just a click away.<\/p>\n<p>At <strong>24&#215;7 WP Support<\/strong>, our team is available around the clock to fix WordPress errors, optimize performance, and secure your site. Whether it&#8217;s a broken AJAX function or a hidden plugin conflict, we solve it fast and professionally.<\/p>\n<p>\ud83d\udc49 Contact<a href=\"https:\/\/www.24x7wpsupport.com\/\"> <strong>24&#215;7 WP Support<\/strong><\/a> today and get instant help from certified WordPress experts. We\u2019re here when you need us \u2014 anytime, anywhere.<\/p>\n<p>Looking for more WordPress help? Subscribe to our<a href=\"https:\/\/www.youtube.com\/@24x7wpsupport\">\u00a0<strong>YouTube Channel<\/strong><\/a>\u00a0for expert video tutorials. Join us on<a href=\"https:\/\/x.com\/24x7wpsupport\">\u00a0<strong>Twitter<\/strong><\/a>\u00a0and<a href=\"https:\/\/www.facebook.com\/24x7wpsupportdotcom\">\u00a0<strong>Facebook<\/strong><\/a>\u00a0for updates, tips, and insights.[\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Last updated on August 6th, 2025 at 05:27 am[vc_row][vc_column][vc_empty_space][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=&#8221;Introduction&#8221; font_container=&#8221;tag:h2|text_align:left|color:%235F91BF&#8221; use_theme_fonts=&#8221;yes&#8221; css=&#8221;&#8221;][vc_column_text css=&#8221;&#8221;]If you run a WordPress website, you &#8230;<\/p>\n","protected":false},"author":1,"featured_media":14392,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1388],"tags":[],"class_list":["post-14390","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-wordpress-error"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Fix WordPress admin-ajax.php 400 Bad Request Error<\/title>\n<meta name=\"description\" content=\"Learn how to fix the WordPress admin-ajax.php 400 Bad Request error. Resolve AJAX issues caused by plugins, URLs, or missing parameters to restore site features.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.24x7wpsupport.com\/blog\/how-to-fix-wordpress-admin-ajax-php-400-bad-request-error\/\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Fix WordPress admin-ajax.php 400 Bad Request Error\" \/>\n<meta property=\"og:description\" content=\"Learn how to fix the WordPress admin-ajax.php 400 Bad Request error. 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