A browser request that sends or retrieves data from the server without reloading the page. WordPress and WooCommerce use AJAX requests for cart updates, checkout processing, form submission, and live search. When an AJAX request fails, the visible result is often a button that does nothing or a form that appears to submit but produces no response. AJAX failures appear as network errors in the browser console and are captured by Loupely alongside any server-side PHP errors that triggered them.