# Rank Math Canonical From an "Original URL" Field

> Replaces the canonical URL with one saved in a custom field on posts republished from elsewhere.

- Type: PHP
- Runs: Frontend only
- Category: [Plugin Integrations](https://wpide.com/library/category/integrations/)
- Tags: rank-math, canonical, syndication
- Author: WPIDE Team
- Installs: 0
- Updated: 2026-10-28
- Page: https://wpide.com/library/rankmath-canonical-from-field/

## Code

```php
// Custom field holding the original URL.
$wpide_rm_canonical_field = 'original_url';

add_filter( 'rank_math/frontend/canonical', function ( $canonical ) use ( $wpide_rm_canonical_field ) {
    if ( ! is_singular() ) {
        return $canonical;
    }

    $source = esc_url_raw( (string) get_post_meta( get_queried_object_id(), $wpide_rm_canonical_field, true ) );

    return wp_http_validate_url( $source ) ? $source : $canonical;
} );
```

## Notes

Add a custom field named original_url with the full source URL.

## How to use it

Install the free WPIDE plugin (https://wordpress.org/plugins/wpide/), find "Rank Math Canonical From an "Original URL" Field" in its snippet library and add it in one click; or create a new PHP snippet in WPIDE (or any code snippets plugin) and paste the code above. More snippets: https://wpide.com/library/