Did you know that WordPress purposefully reduces your image quality? WordPress does this to reduce image filesize which makes web pages load faster. For the majority of websites the minimal quality reduction is probably a good tradeoff for a better user experience for visitors (and SEO).
If however you want ultra crisp and sharp photos on your website then reducing quality of images (using lossy compression) isn’t acceptable.
WordPress by default is set to compress jpeg images up to 90% of their original quality when uploaded to the Media Library. This compression can have a large impact on the image file-size but usually has very little visible quality effect.
For photographers, WooCommerce websites and others that rely on high resolution images then it is preferable to maintain the best photo quality possible.
Fortunately it’s simple to override WordPress from reducing the image quality. Just save the following line to your functions.php file to set the image quality at 100%:
add_filter( 'jpeg_quality', create_function( '', 'return 100;' ) );
Of course you can always use software such as FileOptimizer to reduce image file-size without sacrificing quality (lossless compression).