Description
Duplicate Killer helps you stop duplicate form submissions in WordPress.
If your forms receive the same email address multiple times, fake leads, or repeated submissions, this plugin fixes the problem instantly.
Choose which fields must be unique (email, phone, text) and block duplicate entries automatically — without changing your form design or user experience.
Duplicate Killer works silently in the background and integrates seamlessly with popular WordPress form plugins and page builders.
Supported Plugins
- Contact Form 7
- Elementor Forms
- Forminator
- WPForms Lite
- Breakdance Page Builder Forms
Key Features
✔ Prevent duplicate submissions by Email, Phone or Text fields
✔ Stop duplicate emails and repeated leads
✔ One global error message for all forms (Free version)
✔ Optional IP-based duplicate protection
✔ Store unique entries securely in your WordPress database
✔ Automatically store uploaded files from Contact Form 7
✔ Lightweight, fast and easy to configure
NEW: Elementor Forms Support
Duplicate Killer now fully supports Elementor Forms.
You can prevent duplicate submissions in Elementor contact forms, lead forms and popups by enforcing unique values such as email or phone number.
This feature works with Elementor’s native form widget and requires no additional configuration.
Plugin Integrations
Contact Form 7
- Limit submissions by Email, Phone or Text fields
- Custom validation message for duplicate entries
- Automatically store uploaded files locally
Elementor Forms
- Prevent duplicate submissions on Elementor native forms
- Works with contact forms, lead forms and popups
- Seamless integration without modifying form structure
Forminator
- Select unique fields (Email, Phone, Text)
- Warn users when a value has already been submitted
WPForms Lite
- Prevent duplicate entries without changing form layout
- Clean and simple validation messages
Breakdance Page Builder Forms
- Prevent duplicate submissions on Breakdance native forms
- IP-based validation for cleaner data
- Fully compatible with Breakdance UI
Free vs Pro
Free Version
- Duplicate protection for supported form plugins
- One global error message for all forms
- Basic duplicate detection (Email, Phone, Text)
- Elementor Forms support
Duplicate Killer PRO
- Individual settings for each form
- Custom error message per form
- Limit submissions by IP per form
- Unique entries per user (cookie-based, per form)
- Display submission count per form
- Advanced duplicate protection controls
Installation
- Install Duplicate Killer from the WordPress Plugins screen or upload it to
/wp-content/plugins/. - Activate the plugin from the Plugins menu.
- Open Duplicate Killer from your WordPress admin dashboard.
- Select your form plugin and choose which fields must be unique.
FAQ
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Why should I use Duplicate Killer?
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Duplicate Killer prevents duplicate emails and repeated form submissions, helping you keep your leads and contact data clean.
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How does Duplicate Killer work?
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When a form is submitted, selected field values are stored in the database. If the same value is submitted again, the submission is blocked and a validation message is shown.
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Can multiple users submit the same value?
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Yes. In the PRO version, you can enable “Unique entries per user”, allowing multiple users to submit the same value while blocking repeat submissions from the same user.
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Does it affect form design or styling?
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No. Duplicate Killer works in the background and does not change your form appearance.
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Does it work with Elementor Forms?
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Yes. Duplicate Killer fully supports Elementor Forms.
Reviews
Contributors & Developers
“Duplicate Killer – Stop Duplicate Form Submissions (CF7, Elementor, WPForms, Forminator, Breakdance)” is open source software. The following people have contributed to this plugin.
ContributorsInterested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.4.5
- New feature: Duplicate protection for Elementor Forms
1.4.4
- Bug fix: Undefined array key Forminator
1.4.3
- Bug: Problem with table creation
1.4.2
- Support Number field on Forminator
1.4.1
- Tested up to WordPress 6.9
1.4.0
- Feature: Added support for forms built with Breakdance Page Builder.
1.3.1
- Feature: Automatically store uploaded files from the form (CF7) on your server
1.3.0
- Tested up to 6.8.1
- Feature: Restrict form entries based on IP address
1.2.3
- Feature: Store CF7 files submitted
1.2.2
- Bug: Problem with table creation
- Feature: Add form date submission
1.2.1
- Feature: Store CF7/Forminator/WPForms submissions to your WordPress database
- Tested up to 6.7.2 WordPress
1.2.0
- Bug: Fixed – Custom HTML in CF7 form – issue with detection
1.1.9
- Bug: Fixed only first 3 forms are showing in the “WPForms forms list”
1.1.7
- Bug: Fixed style sheet.
1.1.6
- Bug: Prevent empty values from being detected as duplicate entries.
1.1.5
- Interface to manage the saved values in your WordPress database.
1.1.4
- Duplicate Killer will prevent the entries from being added into CFDB7(Contact Form 7 Database Addon) plugin.
- Tested up to 6.4.1 WordPress’
1.1.3
- Fixed PHP Warning Undefined array key at CF7 function
- Tested up to 6.3.1 WordPress’
1.1.2
- Tested up to 6.1.1 WordPress’
1.1.1
- Fix bug at feature ‘Unique entries per user’
1.1.0
- New feature – Unique entries per user
- New style navigation for better UX
1.0
- First public release



