OpenGraph (by ROBOTSTXT)

Intelligent Open Graph meta tags with automatic image fallback from AVIF/WebP to JPEG/PNG for social media crawlers.

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Description

Social media crawlers — Facebook, Twitter/X, LinkedIn, WhatsApp — do not support modern image formats such as AVIF and WebP. When a post’s featured image uses one of these formats, the platform shows a broken or missing image preview.

OpenGraph (by ROBOTSTXT) outputs a complete set of Open Graph and Twitter Card meta tags and solves the format incompatibility automatically. It detects whether each post’s featured image is in a supported format and, when needed, resolves and caches a compatible JPEG or PNG alternative.

How it works:

1. A visitor (or social media crawler) requests a page.
2. The plugin checks whether the post’s featured image is in AVIF, WebP, or another unsupported format.
3. If so, it locates a JPEG or PNG version of the same image using HTTP HEAD requests.
4. The result is cached in postmeta so subsequent requests are instant.
5. The resolved image is injected into og:image (and related) meta tags.

Key features:

• Full Open Graph meta tag output: og:title, og:type, og:url, og:description, og:site_name, og:locale, og:image, og:image:width, og:image:height, og:image:type, og:image:alt
• Article-specific tags: article:published_time, article:modified_time, article:section, article:tag
• Twitter Card tags: twitter:card, twitter:site, twitter:image
• Automatic format detection — AVIF, WebP, GIF, BMP, SVG, TIFF
• HTTP HEAD-based image verification (no file downloads)
• Per-post custom OG title and description override (post editor meta box)
• Global fallback image URL and homepage-specific image URL
• Cached results in postmeta for performance, with automatic invalidation on featured image change
• Negative caching for failed resolutions (1-hour transient)
• Integration with Yoast SEO and RankMath (no duplicate tags)
• Taxonomy archive image support via developer filter
• Admin panel with Settings, Tools, and Diagnostics tabs
• WP-CLI commands for batch operations
• REST API endpoints for programmatic access
• Multisite compatible (per-site configuration)
• Full internationalization support (es_ES and ca included)

Using the plugin

WP-CLI

List available commands:

wp og-fallback --help

Resolve the fallback image for a single post:

wp og-fallback resolve 123

Re-resolve all posts (clears cache first):

wp og-fallback resolve --all

Dry-run re-resolution without saving:

wp og-fallback resolve --all --dry-run

Re-resolve all posts of a specific type:

wp og-fallback resolve --all --post-type=page

Clear cache for a single post:

wp og-fallback clear-cache 123

Clear all cached fallback URLs:

wp og-fallback clear-cache --all

REST API

The plugin exposes two REST API endpoints under the robotstxt-og/v1 namespace. Both require the edit_others_posts capability (editor and above).

Force re-resolve a post’s fallback image:

POST /wp-json/robotstxt-og/v1/resolve/{post_id}

Returns: { post_id, resolved_url, cached, success }

Get current cached status for a post:

GET /wp-json/robotstxt-og/v1/status/{post_id}

Returns: { post_id, cached_url, original_url, has_cache }

Extra Configurations

Developer filters available in functions.php or a custom plugin:

Disable external image resolution:

add_filter( 'robotstxt_og_external_image_enabled', '__return_false' );

Adjust HEAD request timeout (seconds, default: 5):

add_filter( 'robotstxt_og_external_image_timeout', fn() => 10 );

Provide an OG image for taxonomy archives:

add_filter( 'robotstxt_og_taxonomy_image', fn( $url, $term_id ) => wp_get_attachment_url( get_term_meta( $term_id, 'my_image_id', true ) ), 10, 2 );

Enable debug logging to debug.log:

add_filter( 'robotstxt_og_enable_logging', '__return_true' );