Too many sizes

Wordpress added 1536×1536 and 2048×2048 in 5.3, so it’s quite new. You can turn them off with some code in your functions.php. You can choose the sizes you want. Regenerate will only create thumbnails up to the maximum size of the image. So if you upload images at smaller than 1536×1536, it won’t create those.

function remove_default_image_sizes( $sizes) {
unset( $sizes[‘large’]); // Added to remove 1024
unset( $sizes[‘thumbnail’]);
unset( $sizes[‘medium’]);
unset( $sizes[‘medium_large’]);
unset( $sizes[‘1536×1536’]);
unset( $sizes[‘2048×2048’]);
return $sizes;
}
add_filter(‘intermediate_image_sizes_advanced’, ‘remove_default_image_sizes’);

Thanks. That led to a rabbit hole of interesting articles, especially the one about PNGs gettnig upsized.

I’m still working on how my specific setup (Astra theme) has processed all the size-generating rules. I think I am getting all the registered sizes up to but not beyond the size of what I upload. That makes sense and is consistent with your explanation.

Glad to be of help ??
regenerate is quite helpful as it shows the existing sizes registered in your theme. I had a bunch of sizes manually registered, and recently went down the rabbit hole myself trying to figure out which plugin had decided to add 1536 and 2048 thumbnails everywhere. Turns out it was just WP…