Images Get Pixelated When Uploading
If your images turn out pixelated, even after uploading the correct resolution, you may be experiencing one of the following:
Double check the selected image size
Double check whether the size of the selected image is correct. Edit the image and it should bring up the media Manager, check to see if your uploaded image is set to a large enough size, e.g. Full Size. If the full size dimensions are too small, try uploading a higher resolution image and try this step again.
Remove support for WordPress' responsive image feature
WordPress has a built-in feature for responsive images whereby a different sized image is displayed depending on the browser's size. While this is a great feature, we have encountered times when a theme did not render good resolution images when responsive images are used. You can disable this feature by inserting this code into your
add_filter( 'wp_calculate_image_srcset', '__return_false' );
Special thanks to Viktor Horecny for the help regarding responsive images!