How to Scale Large Images for Episode Cover Art

Since WordPress 5.3, large images are automatically scaled to a default maximum of 2560px in either dimension. Since podcast and episode artwork needs to be 3000px by 3000px, you can override this by using a filter in your theme's functions.php file.

Step-by-Step Instructions

1. Open Your Theme's functions.php

You can do this through:

WordPress Dashboard → Appearance → Theme File Editor → functions.php

Or via FTP/SFTP: /wp-content/themes/your-theme/functions.php

2. Add This Code to Change the Limit to 3000px

add_filter( 'big_image_size_threshold', 'custom_big_image_size_threshold', 10, 4 );

function custom_big_image_size_threshold( $threshold, $imagesize, $file, $attachment_id ) {

return 3000;

}

3. Save the File

Now WordPress will scale down uploaded images only if they exceed 3000px in width or height.

Optional: To turn off the large image scaling entirely, you can return false through the same filter.

1. Open Your Theme's functions.php

You can do this through:

WordPress Dashboard → Appearance → Theme File Editor → functions.php

Or via FTP/SFTP: /wp-content/themes/your-theme/functions.php

2. Add This Code to Disable Scaling

add_filter( 'big_image_size_threshold', '__return_false' );

This tells WordPress to never scale large images.

3. Save the File

WordPress will now upload images exactly as-is, with no auto-scaling.

Note: If you're using a child theme, always edit the child theme's functions.php. Additionally, since this may have performance and storage implications and should only be done with the website owner's consent or by their developer.

Updated on: 23/01/2026