Description
Duplicate Title Validator is a robust WordPress plugin designed to ensure the uniqueness of post titles across all post types and taxonomies. By preventing duplicate titles, this plugin enhances both SEO and user experience. Whether you use Gutenberg or the Classic Editor, it seamlessly integrates to maintain title uniqueness.
Key Features
- Comprehensive Duplicate Detection: Scans selected post types (including custom ones) and taxonomies to identify duplicate titles. Case-insensitive comparison catches duplicates regardless of capitalisation.
- Post Type Selection: Choose which post types are included in duplicate title checking from the settings page.
- Gutenberg Publish Lock: In the block editor, the Publish button is fully disabled when a duplicate title is detected, with a pre-publish warning panel showing the conflicting titles.
- Classic Editor Protection: Automatically saves posts with duplicate titles as drafts to prevent accidental publishing, with a dismissible admin notice.
- Forbidden Words Filter: Define a list of words or phrases that must not appear in post titles. Choose to block publishing entirely or show a warning while allowing publishing.
- Admin Email Notifications: Configure one or more admin email addresses to receive an alert whenever a post with a duplicate title is published. Includes 5-minute throttling to prevent spam.
- Duplicate Title Report: A dedicated report page lists all published posts with duplicate titles, grouped by title, with direct edit links.
- Real-time Similar Titles: As you type a title, a live list of similar existing titles appears below the input field in both editors.
- Dashboard Widget: A dedicated widget on the WordPress dashboard identifies similar or potentially duplicate titles using cosine similarity, with colour-coded scores and direct edit links.
- Redesigned Settings Page: A clean, card-based settings UI with toggle switches, inline field descriptions, and a test email button.
- Result Caching: Dashboard widget results are cached for one hour to avoid performance issues on large sites.
- Mobile Optimised: All admin pages and widgets are fully responsive at the 782px WordPress mobile breakpoint.
- Localization Support: Fully translated into 6 languages – English, Persian, Spanish, Portuguese (Brazil), German, and Arabic – with support for adding more.
New in Version 1.8
- Forbidden Words Filter: Block publishing or show a warning when a post title contains configured words or phrases. Integrated into both Gutenberg and the Classic Editor.
- Admin Email Notifications: Notify one or more admins when a duplicate title is published. Configurable email list with a Send Test Email button. 5-minute throttling prevents notification spam.
- Post Type Selection: Choose which post types are checked for duplicate titles. Leave all unchecked to check all public post types.
- Duplicate Title Report Page: A new submenu page lists all published posts with duplicate titles, grouped by title, with post type badges and direct edit links.
- Case-insensitive Comparison: Duplicate detection now uses LOWER() in SQL so “Hello” and “hello” are treated as the same title.
- Mobile Optimisation: Settings page, report page, and dashboard widget are now fully responsive.
- Bug Fixes: Fixed WooCommerce notice disappearing too quickly, fixed similar titles box hiding on exact duplicate match, fixed pair_key duplication bug in dashboard widget, fixed textdomain loading timing.
- All Language Files Updated: All 5 translations (fa_IR, ar, de_DE, es_ES, pt_BR) updated with all new strings.
Supported Languages
This plugin ships with built-in translations. No extra installation required – activate the plugin and set your WordPress language.
- English (en_US) – Built-in
- Persian / فارسی (fa_IR) – Complete
- Spanish / Español (es_ES) – Complete
- Portuguese Brazil / Português (pt_BR) – Complete
- German / Deutsch (de_DE) – Complete
- Arabic / العربية (ar) – Complete
Want to add your language? Translate the .pot file in the languages/ folder using Poedit and send the .po and .mo files to hasan.mova@gmail.com.
Translators
- Persian (fa_IR): Hasan Movahed
- Spanish (es_ES): Hasan Movahed
- Portuguese Brazil (pt_BR): Hasan Movahed
- German (de_DE): Hasan Movahed
- Arabic (ar): Hasan Movahed
Special Thanks
A heartfelt thank you to May for her generous financial support – you believed in this project when it needed it most and kept it alive. This plugin exists because of your kindness. Thank you.
Support & Donations
This plugin is free and open-source, built and maintained entirely in spare time. If it saves you time or helps your site stay organised, please consider supporting its development.
Every contribution, no matter how small, helps keep this project alive and growing.
To send a donation or get in touch: hasan.mova@gmail.com
License
This plugin is licensed under the GPLv2 or later license.
Contributing
Contributions are welcome! Fork the repository and submit a pull request. Ensure your code adheres to WordPress coding standards.
Support Forum
For assistance, visit the WordPress.org support forum.
Screenshots
Installation
Steps to Install the Plugin
Upload the Plugin:
- Upload the
duplicate-title-validatefolder to the/wp-content/plugins/directory.
- Upload the
Activate the Plugin:
- Go to Plugins > Installed Plugins in your WordPress dashboard.
- Locate Duplicate Title Validator and click Activate.
Configure Settings (Optional):
- Navigate to Duplicate Title Validator > Settings in the WordPress admin menu to adjust the plugin settings.
FAQ
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Does this plugin support custom post types and taxonomies?
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Yes, it checks for duplicate titles across all registered post types and taxonomies, including custom ones. You can also limit checking to specific post types from the Settings page.
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What happens in Gutenberg when a duplicate title is detected?
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The Publish button is locked via the official
lockPostSavingAPI and a warning panel appears in the pre-publish checklist listing all conflicting titles. The lock is released as soon as the title is changed to a unique one. -
What happens in the Classic Editor?
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The post is saved as a draft instead of being published, and an admin notice is displayed explaining the duplication source.
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Can I allow duplicate titles if I need to?
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Yes. Go to Duplicate Title Validator > Settings and enable “Allow Duplicate Titles.” In Gutenberg this shows a dismissible warning instead of blocking publishing.
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What are Forbidden Words?
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You can define a list of words or phrases that must not appear in post titles. In Block mode, publishing is prevented entirely. In Warn mode, a notice is shown but the post can still be published.
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How do admin email notifications work?
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Enter one or more admin email addresses in the Settings page. Whenever a post with a duplicate title transitions to “published”, the configured admins receive an email alert. A 5-minute throttle per post prevents duplicate notifications.
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Is duplicate title detection case-sensitive?
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No. Comparison uses LOWER() in the database query, so “Hello”, “hello”, and “HELLO” are all treated as the same title.
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Can I translate this plugin into other languages?
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Absolutely. The plugin is translation-ready with a
.potfile in thelanguages/folder. Create.poand.mofiles using Poedit and place them in thelanguages/directory. -
Does the plugin affect site performance?
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The plugin is optimised for performance. Dashboard widget results are cached for one hour. On very large sites, the similarity scan limit can be reduced in the settings. Duplicate checking queries are lightweight and indexed.
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How do I update the plugin?
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Updates can be done directly via the WordPress dashboard. Always back up your site before updating.
Reviews
Contributors & Developers
“Duplicate Title Validator” is open source software. The following people have contributed to this plugin.
Contributors
“Duplicate Title Validator” has been translated into 1 locale. Thank you to the translators for their contributions.
Translate “Duplicate Title Validator” into your language.
Interested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.8
- New: Forbidden words/phrases filter – block publishing or show a warning when a title contains configured words. Integrated into Gutenberg (lockPostSaving) and Classic Editor (AJAX + server-side).
- New: Admin email notifications – notify one or more admins when a duplicate title is published, with 5-minute transient throttling to prevent spam.
- New: Post type selection – choose which post types are included in duplicate title checking from the settings page.
- New: Duplicate Title Report submenu page – lists all published posts with duplicate titles grouped by title, with post type badges and edit links.
- New: Send Test Email button on the settings page to verify mail server configuration.
- New: Case-insensitive duplicate detection using LOWER() in SQL queries.
- Fix: WooCommerce duplicate notice was disappearing too quickly – removed premature transient deletion so it persists for 60 seconds.
- Fix: Similar titles box was hiding when the user typed an exact duplicate title – removed the erroneous exact-match filter from get_matching_titles().
- Fix: pair_key bug in dashboard widget causing the same similar-title pair to appear twice – replaced min/max logic with sort() on full ID|type strings.
- Fix: load_plugin_textdomain was called inside a plugins_loaded callback hooked from init, which meant it never fired – changed to a direct call in the constructor.
- Fix: Removed em dashes from all UI strings for better cross-font compatibility.
- Mobile: Settings page, report page, and dashboard widget are fully responsive at the 782px WordPress admin breakpoint.
- i18n: All 5 language files (fa_IR, ar, de_DE, es_ES, pt_BR) updated with all new strings from v1.8.
1.7
- New: Gutenberg Publish button fully locked via
lockPostSavingwhen a duplicate title is detected and “Allow Duplicate Titles” is off. - New: Pre-publish panel in the block editor showing conflicting titles and a clear explanation.
- New: Colour-coded meta box result panel in the block editor sidebar (red for duplicates, green for clean).
- New: Completely redesigned settings page with a card-based UI, dark header, and toggle switches.
- New: Completely redesigned dashboard widget with similarity score badges and grouped title cards.
- New: Donation and support section added to both the settings page and the dashboard widget.
- New: Added full translations for Spanish (es_ES), Portuguese Brazil (pt_BR), German (de_DE), and Arabic (ar).
- Fix: Corrected
load_plugin_textdomainpath (was pointing toinc/languagesinstead oflanguages). - Fix: Fixed wrong text domain
'textdomain'inclass-title_checker.php. - Fix: Replaced flawed
strpos-based similar title filter with a direct equality check. - Fix: Removed duplicate
wp-pluginsentry from Gutenberg script dependencies. - Fix: Added
sanitize_text_field()andabsint()to Gutenberg REST API request handlers. - Fix: Removed unused
/check-titlesREST API endpoint. - Fix: Dashboard widget now checks for
WP_Errorreturn fromget_terms(). - Fix: Removed
error_log()calls from production code. - Performance: Dashboard widget results cached with a one-hour transient.
- Performance: Duplicate pair tracking in similarity scan avoids redundant comparisons.
1.6
- Restructured plugin architecture for better performance and maintainability.
- Added a dashboard widget to identify and manage similar titles.
- Introduced a feature to display previously used titles.
- Improved compatibility with Gutenberg and Classic Editor.
- Enhanced localization support for English and Persian.
1.5
- Standardization based on the structure required by WordPress support.
1.4
- Enhanced taxonomy duplication checks.
- Improved localization support for Persian.
- Refined error message clarity.
- Optimized performance for larger datasets.
1.3
- Refactored plugin structure to object-oriented.
- Added comprehensive taxonomy support.
- Improved compatibility with WordPress updates.
1.2
- Introduced localization.
- Enhanced duplication source identification.
1.1
- Improved handling of complex REST API responses.
- Enhanced Classic Editor support.
1.0
- Launched with core functionality for duplicate title detection.
