Description
Block Accessibility Checks is a comprehensive WordPress plugin that proactively prevents accessibility issues in your content before they reach your audience. Designed for the Gutenberg block editor, it provides real-time validation that ensures your images, buttons, tables, headings, and galleries meet WCAG (Web Content Accessibility Guidelines) requirements.
Unlike reactive accessibility tools that scan published content, this plugin catches problems during the editing process—giving immediate visual feedback and preventing publication of content with critical accessibility errors. Content creators get clear guidance on what needs fixing, while developers can extend the system with custom checks for any block type.
Whether you’re a content creator ensuring your posts are accessible, a developer building accessible blocks, or an organization maintaining compliance standards, Block Accessibility Checks provides the tools you need to create inclusive content effortlessly.
Key Features:
- Real-time Visual Feedback – See accessibility issues instantly with color-coded borders around problematic blocks and detailed error messages in the block inspector panel
- Smart Publishing Control – Prevents publication of content with critical accessibility errors while allowing warnings with user awareness
- Comprehensive Block Coverage – Built-in checks for images, buttons, tables, headings, and galleries with multiple validation rules per block type
- Advanced Heading Validation – Document-wide hierarchy checking prevents skipped heading levels and ensures proper content structure
- Intelligent URL Validation – Real TLD validation using the Public Suffix List ensures only legitimate domains are accepted
- Configurable Settings – Granular control over each check’s severity (error/warning/disabled) with an intuitive admin interface
- Issue Categorization – Clear distinction between accessibility issues and validation errors for better understanding
- Developer-Friendly API – Comprehensive hooks and filters system for registering custom accessibility checks
- External Plugin Support – Works seamlessly with custom blocks from third-party plugins and themes
How It Works:
The plugin provides immediate feedback as you edit content. When accessibility issues are detected, blocks are highlighted with visual indicators and detailed messages explain how to fix the problems. Critical errors prevent publishing until resolved, while warnings allow publication with user acknowledgment.
Built-in Accessibility Checks:
- Button Blocks – Ensures buttons have descriptive text content and valid link destinations with real URL validation
- Image Blocks – Requires alt text (unless marked decorative), validates length, prevents caption duplication, and detects non-descriptive patterns
- Table Blocks – Requires proper headers or captions for screen reader navigation
- Heading Blocks – Validates proper heading hierarchy (no skipped levels), ensures appropriate first heading level, and configurable heading level restrictions
- Gallery Blocks – Applies comprehensive image accessibility checks to all gallery items
Perfect For:
- Government websites requiring WCAG compliance
- Educational institutions with accessibility mandates
- Businesses committed to inclusive web content
- Developers building accessible WordPress themes and plugins
- Content teams who want accessibility guidance built into their workflow
Developer API:
Extend the plugin with custom accessibility checks for any block type. The robust API includes registration functions, validation hooks, and automatic JavaScript integration. Perfect for plugin developers who want to add accessibility validation to their custom blocks.
Getting Involved
If you would like to get involved and contribute to the development of this plugin or view it’s source code you can find more information in the plugins GitHub repo.
Screenshots

Block Error Validation – Button block showing accessibility error with red border and detailed error message preventing publication, also demonstrates multiple errors in a grouped display 
Visual Warning System – Image block displaying accessibility warning with clear explanation in the block inspector panel, also demonstrates multiple warnings in a grouped display 
Heading Level Management – Customized heading level restrictions maintaining proper content hierarchy in the editor 
Table Header Validation – Table block showing accessibility error with red border and detailed error message preventing publication 
Comprehensive Settings Panel – Plugin configuration page with granular control over accessibility check severity levels 
External Block Validation — A custom external card block leveraging the block checks system 
External Block Settings Panel — A custom external card block leveraging the block checks system
Installation
From WordPress Admin:
1. Go to Plugins Add New in your WordPress admin
2. Search for “Block Accessibility Checks”
3. Click “Install Now” and then “Activate”
4. Navigate to Settings Block Accessibility Checks to configure your preferences
Manual Installation:
1. Download the plugin files and upload to /wp-content/plugins/block-accessibility-checks/
2. Activate the plugin through the Plugins menu in WordPress
3. Configure your accessibility check preferences in the settings
After Installation:
Visit Settings Block Accessibility Checks to customize which checks should be errors, warnings, or disabled. The plugin works immediately after activation with sensible defaults.
FAQ
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How do I use this plugin?
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- Once activated, navigate to Settings Block Accessibility Checks to configure your preferences
- Choose which checks should be errors (prevent publishing) or warnings (allow publishing with notice)
- Start editing content in the Gutenberg editor – accessibility checks run automatically
- Blocks with issues will show red borders and error messages in the block inspector panel
- Fix the highlighted issues or adjust check severity levels as needed
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What happens when accessibility issues are found?
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The plugin provides immediate visual feedback:
* Red borders around blocks with accessibility problems
* Detailed error messages in the block inspector sidebar panel
* Publishing prevention for critical errors (configurable)
* Warning indicators for less critical issues that still allow publishing -
Can I add custom accessibility checks for my own blocks?
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Yes! The plugin includes a comprehensive developer API with extensive hooks and filters. You can register custom accessibility checks for any block type, including custom blocks from your themes or plugins. See the developer documentation for complete examples.
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Does this work with blocks from other plugins?
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Absolutely! The plugin’s architecture supports any WordPress block, whether from core, themes, or third-party plugins. Developers can easily integrate their custom blocks with the accessibility checking system.
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Can I configure which checks are errors vs warnings?
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Yes, most checks can be configured as errors (prevent publishing), warnings (allow publishing with notice), or disabled entirely. Visit the plugin settings page to customize the behavior for your needs.
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Will this slow down my editor?
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No, the plugin is optimized for performance with smart caching and efficient validation algorithms. Checks run in real-time without impacting editor responsiveness.
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How to uninstall the plugin?
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Simply deactivate and delete the plugin through the WordPress admin interface.
Reviews
There are no reviews for this plugin.
Contributors & Developers
“Block Accessibility Checks” is open source software. The following people have contributed to this plugin.
Contributors“Block Accessibility Checks” has been translated into 1 locale. Thank you to the translators for their contributions.
Translate “Block Accessibility Checks” into your language.
Interested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
View the changelog on the plugin website.
