So you have a great looking new WordPress site design, but are not quite sure what image size you should be uploading to WordPress. Maybe you have a full-width background image or hero image. What size should the background image be? 1000px, 2000px, 3000 px or higher? With today’s multi format, multi device world, deciding what image size you need to upload to your new WordPress site can be very confusing. Even among the professionals.

Quelle: The Ultimate Guide To Image Sizes for WordPress | WP Hero – WooCommerce Support & Optimization