Critical CSS for WP

Critical CSS for WP generates and stores critical CSS for published WordPress content using a configurable HTTP API endpoint. It injects the generated CSS inline on the frontend and can defer render-blocking styles when a page has critical CSS available.

Features

• Generates CSS for published posts, pages, and other public post types
• Stores generated CSS in post meta using the _critical_css key
• Injects the CSS inline in the page head via wp_head
• Defers non-critical enqueued styles using the media="print" onload="this.media='all'" pattern
• Supports manual regeneration from the settings screen, bulk actions, and single-post actions
• Uses WP Cron for scheduled regeneration with configurable intervals and thresholds
• Provides a settings page under Settings → Critical CSS

Configuration

1. Activate the plugin.
2. Open Settings → Critical CSS.
3. Set the API URL for the critical CSS service.
4. Select enabled post types.
5. Save the settings and trigger a manual regeneration if needed.

Notes

• The API endpoint is configurable so it can be changed later without changing code.
• The plugin keeps the implementation simple and extendable for future API changes.
• Logs are written to the WordPress debug log when WP_DEBUG and WP_DEBUG_LOG are enabled.