lazy load iframes will break sites with ads

There is a filter you can use. And the attribute only applies to images or iframes that have both width and height.

We need a super easy way to turn off lazy load of iframes in WP 5.7 as it will break sites where ads are placed by 3rd party ad agencies who use their own lazy load.

This can be done:

Lazy-loading iframes in 5.7

Here is an example code snippet which would disable lazy-loading iframes that embed YouTube videos within post content:

function skip_loading_lazy_youtube_iframes( $value, $iframe, $context ) {
    if ( 'the_content' === $context && false !== strpos( $iframe, 'youtube.com' ) {
        return false;
    }
    return $value;
}
add_filter(
    'wp_iframe_tag_add_loading_attr',
    'skip_loading_lazy_youtube_iframes',
    10,
    3
);

Change out youtube.com to whatever you use for ads ??

https://make.www.ads-software.com/core/2020/07/14/lazy-loading-images-in-5-5/#customizing-lazy-loading has more details.

Since this is not a support post, however, I’m closing it. There’s nothing wrong or broken in 5.7.

Discussion continues at https://core.trac.www.ads-software.com/ticket/52692