Duplicate Killer – Prevent Duplicate Form Submissions

Duplicate Killer is a WordPress plugin by NIA, first published on WordPress.org in 2022. It has 1,000+ active installations and 32,919 downloads in total, and ranks #5,975 in the WordPress.org plugin directory. Over the past week it climbed 26 places. Users rate it 5.0 out of 5 across 3 reviews. Version 1.7.6 was released 2 days ago, so the plugin is actively maintained. It is tested up to WordPress 7.1.3 and requires WordPress 5.3 and PHP 5.6.20 or later. No support threads were opened in the last two months. It is listed under contact form 7, duplicate-orders, elementor forms, forminator and woocommerce. Plugins with a similar focus include Smart Phone Field For WPForms, Contact Form 7, Fluent Forms, Elementor Forms, WooCommerce, Formidable Forms, Ninja Forms, WPGSI and 360 Javascript Viewer.