Is Duplicate Killer free?

Duplicate Killer offers a free version with core features. A premium version is also available with additional functionality.

How many websites use Duplicate Killer?

Duplicate Killer has 1.0K+ active installations as tracked by WordPress.org.

What are the best Duplicate Killer alternatives?

Popular alternatives to Duplicate Killer include Google for WooCommerce, WooCommerce PayPal Payments, WooCommerce Stripe Payment Gateway. You can compare them side-by-side on our comparison pages.

Does Duplicate Killer work with the latest WordPress?

Duplicate Killer has been tested up to WordPress 6.9.4. It requires WordPress 5.2+ and PHP 5.6.20+.

Is Duplicate Killer well supported?

Duplicate Killer has a 100% support resolution rate based on 1 recent support threads on WordPress.org.

PluginSift

Duplicate Killer – Prevent Duplicate Form Submissions

Block duplicate form submissions by validating unique email, phone and text fields — without CAPTCHA.

By NIA·Woocommerce·Free + Premium

5(3 reviews)

·1.0K+ active installs·Updated Today

Download Compare

As of April 2026, Duplicate Killer is a WordPress woocommerce plugin with 1.0K+ active installations and a 5/5 rating from 3 reviews. It has been downloaded 20K+ times in total. Requires WordPress 5.2+ and PHP 5.6.20+. Available on WordPress.org since 2022. Actively maintained — updated within the last month. Downloads are down 8% this week. Support resolution rate: 100%. Top alternative: Google for WooCommerce.

5/53 reviews

1.0K+active installs

100%resolved

4 yearssince 2022

Overview

Duplicate Killer – Block Duplicate Form Submissions in WordPress.

WooCommerce – Prevent Accidental Duplicate Orders

Duplicate Killer also protects WooCommerce Classic Checkout from accidental duplicate orders.

WooCommerce already disables the “Place order” button, but duplicate orders can still happen when:

Checkout is slow
Payment gateways lag or retry
Customers refresh the page
Multiple tabs are used
Network requests are retried

Duplicate Killer FREE adds lightweight server-side duplicate protection for WooCommerce Classic Checkout.

If the same customer attempts to submit an identical order within 60 seconds, the duplicate is blocked and a validation message is shown.
!!! No changes to your checkout design. No impact on performance. No additional configuration required.

If your forms…

Read full description on WordPress.org

Screenshots

Ratings & Reviews

53 reviews

5 ★

4 ★

3 ★

2 ★

1 ★

Recent Reviews

Great and straightforward plugin

by jeng22·1 year ago

Plugin is straightforward and the support is really responsive and helpful.

Fixed the issue with duplicate CF7 Emails!!

by hambad·2 years ago

There seems to be an issue with CF7 where duplicate emails are sent out, and the forms render errors/loading spinners twice as well. I’ve done a good bit of research and looked everywhere, but had no luck finding a fix for this. This plugin resolved the issue straight away with no configuration needed! Thank you!

Works like a charm

by peterlovescola·2 years ago

This solves my duplicate entries headache – works as intended. Thanks!