Sometimes you need to upload a high-resolution image to the WordPress Media Library. Maybe it’s because the image contains text, design details, or you simply need maximum quality. However, by default WordPress automatically down-scales any image larger than 2560px on its longest side.
This means that every time you upload a “too big” image, WordPress creates a resized version capped at 2560px. You can recognize it easily by the filename — WordPress appends -scaled to it. For example:
xyz.jpg → becomes xyz-scaled.jpg
Once an image is scaled down, its quality is reduced — which can make it appear blurred or rasterized on the front-end.
The good news is: WordPress still keeps the original full-size file on your server, so it’s not lost.
If you want to disable this automatic downscaling completely, just add the following snippet to your functions.php:
add_filter( 'big_image_size_threshold', '__return_false' );Or, if you prefer to adjust the threshold (instead of turning it off), you can specify your own maximum size. For example, to allow uploads up to 4000px before scaling:
add_filter( 'big_image_size_threshold', function( $threshold ) {
return 4000; // max width or height before WordPress scales
});
