Block Accessibility Checks

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 with a three-tier system that ensures your blocks, post meta fields, and overall document structure 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 blocks, meta fields, and editor-level validation.

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.

Features for Content Creators & Editors:

• Real-time Visual Feedback – See accessibility issues instantly with color-coded borders (red for errors, yellow for warnings) around problematic blocks and detailed error messages in the block inspector panel
• Smart Publishing Control – Critical accessibility errors prevent publishing until resolved, while warnings allow publication with user awareness
• Comprehensive Block Coverage – Built-in validation for images, buttons, tables, headings, and galleries with clear guidance on how to fix issues
• Document-Wide Validation – Advanced heading hierarchy checking prevents skipped heading levels and ensures proper content structure across your entire post
• Title Validation – Ensures posts and pages have a title set for accessibility and SEO, validates in real-time as you type
• Intelligent URL Validation – Real TLD validation using the Public Suffix List ensures only legitimate domains are accepted in button links
• Configurable Settings – Control which checks are errors (prevent publishing), warnings (allow with notice), or disabled through an intuitive admin interface
• Grouped Error Display – All accessibility issues shown at once in organized groups, eliminating the “fix one, see another” frustration
• Works Everywhere – Validation runs in both the post editor and site editor (templates/template parts) with separate configurable settings

Features for Developers & Plugin Authors:

• Three-Tier Validation API – Register custom checks for block attributes, post meta fields, and editor-level validation using comprehensive hooks and filters
• JavaScript-Only Validation – All validation logic runs in JavaScript for real-time editor feedback without server round-trips
• Automatic Settings Integration – External plugins automatically get their own settings pages under the Block Checks menu
• External Plugin Support – Works seamlessly with custom blocks from third-party plugins and themes
• Extensive Hook System – 20+ action and filter hooks for complete customization of registration, validation, and display behavior
• Well-Documented API – Complete developer documentation with quick start guides and working code examples

How It Works:

The plugin provides immediate feedback as you edit content through a sophisticated three-tier validation system:

1. Block Validation – Validates individual block attributes in real-time as you type and edit
2. Meta Field Validation – Checks required post meta fields with automatic post locking when validation fails
3. Editor-Level Validation – Validates document-wide concerns like heading hierarchy that span across multiple blocks

When accessibility issues are detected, they are highlighted with visual indicators (red for errors, yellow for warnings) 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 validates link destinations using real TLD validation (Public Suffix List)
• Image Blocks – Requires alt text (unless marked decorative), validates alt text length (warns if exceeding 125 characters), prevents caption duplication, and detects non-descriptive patterns like “image of” or “photo123”
• Table Blocks – Requires proper headers or captions for screen reader navigation
• Heading Blocks – Validates proper heading hierarchy across entire document (prevents skipped levels), ensures appropriate first heading level (H2 recommended, H1 allowed with warnings), and provides configurable heading level restrictions (H1, H5, H6 can be disabled)
• Gallery Blocks – Applies comprehensive image accessibility checks to all gallery items (alt text, length, patterns, caption duplication)
• Post & Page Title Validation – Ensures posts and pages have a title set for accessibility and SEO, validates in real-time as users type, prevents publishing content without a title, configurable independently for posts and pages
• Post Meta Fields – Validate required custom fields with real-time validation, automatic post locking for errors, and seamless integration with block validation system

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 Resources:

Extend the plugin with custom accessibility checks using the comprehensive validation API. See the complete developer documentation for quick start guides, API reference, code examples, and a working example plugin.

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.