Exclude featured image from WP fastest cache lazy load

Hi there,

Are you referring to the featured images on the blog page or single posts?

Let me know :)

Hi Leo,
single posts and pages.

Can you give this a shot?

add_filter( 'wp_get_attachment_image_attributes', function( $attrs ) {
    if ( is_single() || is_page() ) {
        $attrs['data-skip-lazy'] = '1';
    }

    return $attrs;
} );

Adding PHP: https://docs.generatepress.com/article/adding-php/

Hi Leo,
I inserted the code and it seems to work. Page Speed Inside gives me now CLS=0.
Can you please verify from your side if it is ok.
Thank you.

Don't think you've provided the site link but I assume it's all good :)

Oh sorry, the site is https://www.tourist-in-rom.com/en/ , thank you :) .

Looking into the waterfall, the featured images on posts are immediately loaded but on pages are after the blank.gif
Post: https://test.tourist-in-rom.com/en/rome-december/
Page: https://test.tourist-in-rom.com/en/

Not sure if I fully understand,

This page doesn't have a featured image.

You're right, sorry. The featured image is defined as background image of the page hero.
https://test.tourist-in-rom.com/wp-content/uploads/2020/06/Tourist-in-Rom-Piazza-del-Popolo-100518.jpg

So we are all good now?

I don't believe you can add a data attribute to background images.

@Leo – thanks for this snippet!

The only place on my site that Featured Images (post thumbnails) are displayed is on archive and index (home) pages... So, I tweaked the snippet a bit to force loading only on the first Featured Image on the page, but then leave the rest to be lazy loaded:

add_filter( 'wp_get_attachment_image_attributes', function( $attrs ) {
	global $wp_query;

	if ( $wp_query->current_post === 0 )
		$attrs['data-skip-lazy'] = '1';

	return $attrs;
} );

If you want to disable lazy loading on more than just the first one, then you could just change the conditional in the snippet (e.g., < 3 to load the first three on the page, instead of === 0 to load only the first).

Thanks for sharing!