By default WordPress uses 90% quality for all images served in your website, log posts etc. This is done for conserving space and bandwidth. But still if you want you can force your WordPress JPEG image quality to be 100%.
All you will be needing to do is open your theme’s function.php file and add the following code:
add_filter( 'jpeg_quality', 'jbl_jpeg_quality' );
function jbl_jpeg_quality() {
return 100;
}
OR, alternatively you can use Force jpeg quality plugin. Simply install and activate the plugin and it does the same thing. Thanks to Joan Boluda for this plugin and hack.