OG images in WordPress

A plain functions.php hook has nowhere safe to keep a signing secret — it's plain PHP in your theme's source, often synced or backed up in the clear — so the signed GET /i/{keyId}/{sig} route (Signing) isn't a good fit here. A public key works with nothing more than add_action and the post's own fields.

The plugin

The ogmake OG Images plugin adds og:image and twitter:image to every post, page and chosen custom post type, built from the title, excerpt, author and site name. It has a per-post override meta box and works with Yoast SEO and Rank Math. Download the zip from the GitHub releases page, upload it under Plugins, then Add New, then Upload Plugin, and enter your key id under Settings, ogmake.

Prefer no plugin? The snippet below does the core job in a few lines.

1. Create a public key

Sign in at /login and open the dashboard. Click New key, choose Public key, select which templates the key may render (e.g. blog), then Create key. The key id (starts with k_) is safe to hard-code in your theme.

Still on a hand-issued beta key? Email support@ogmake.com.

2. Hook it into wp_head

In your theme's functions.php:

function ogmake_meta_tags() {
    if ( ! is_single() ) {
        return;
    }
    $params = array(
        'site'   => 'example.com/blog',
        'author' => get_the_author(),
        'date'   => get_the_date( 'M j, Y' ),
        'title'  => wp_strip_all_tags( get_the_title() ),
    );
    $url = 'https://ogmake.com/p/{your-public-key}/blog?' . http_build_query( $params );
    printf(
        '<meta property="og:image" content="%s">' . "\n",
        esc_url( $url )
    );
}
add_action( 'wp_head', 'ogmake_meta_tags', 5 );

Gotcha: an SEO plugin is probably already printing an og:image tag

Yoast SEO, Rank Math and similar plugins hook wp_head too, and by default they'll emit their own og:image from the post's featured image (or nothing, if there isn't one) — most browsers and crawlers use the first matching tag, so whichever hook fires first wins, and having both can produce an inconsistent preview across platforms. The priority 5 above runs before most SEO plugins' default priority (usually 10); to be sure yours wins, disable the plugin's own social image output for the post types you're covering (most SEO plugins have a setting for this) rather than relying on hook order alone.

Verify it

View source on a published post (curl -s https://yoursite.com/some-post/ | grep 'og:image') and confirm exactly one og:image tag is present. A bad or missing field on the public route is still a 200 fallback image, not a visible error — curl -I the image URL itself and check for x-ogmake-error (see debugging a public URL). If a page-caching plugin (WP Rocket, WP Super Cache, host-level full-page cache) is active, purge the cache before re-checking — a stale cached HTML page will keep serving the old tag regardless of what functions.php now outputs. Then run the live URL through Facebook's Sharing Debugger or LinkedIn's Post Inspector; if you edit a post without changing title/author/date, the image URL is identical and the crawler's own cache can still show the old preview — append a v query param (e.g. get_the_modified_time()) to force a fresh scrape. The OG image checker shows what a crawler sees without waiting on either platform's cache.

Cost

The Free plan includes 100 renders a month with no card. Paid plans start at $12 a month for 2,000 renders (Starter) and $24 for 10,000 (Scale). A render is counted the first time a new image is made; repeat requests for the same URL are served from cache. Details on pricing.