When you create a blog post in WordPress, one of the options you have is to add a “Featured image” to the post. The featured image becomes a top banner image for the post (like the combined WordPress and aento banner at the top of this post) and is displayed in post archives (lists or grids of posts) and at the top of the post itself.
Because the featured image is automatically displayed in different sizes across your WordPress site, it is important that you follow some simple rules when creating and uploading your featured image to ensure that it always displays as you expect.
The simple rule
You should create your featured image to have a size of 1080 x 675 pixels.
This is the recommended size for all WordPress based websites built for clients by aento and should also work well on other WordPress websites.
Your featured image will often be displayed at a smaller size than the original 1080 x 675 but the smaller versions of the image (thumbnails) will be automatically generated by WordPress.
The science
There are two key factors in determining what size to create your images:
- The original image size needs to be big enough to allow WordPress to automatically create the required smaller thumbnail versions.
- The aspect ratio of the image, the ratio of the image width to image height, needs to be such that it allows the image to be displayed in full without cropping (hiding or removing) parts of the image. The general aspect ratio used for featured images on aento built websites is 1.6:1
Using an original image size of 1080 x 675 pixels allows both of the above factors to be satisfied.
Image file size
The file size in bytes of the original image is also an important consideration. In order to maintain fast website page load speeds, it is important that we do not use assets, such as images, that are going to slow down website performance because of their size in bytes.
aento built websites will automatically try to compress uploaded images to achieve an optimum image file size without losing quality of the image. The CDN used by aento web hosting further optimises images automatically. These two features provide a good “failsafe” that your website pages will continue to perform well and load quickly.
However, if you are creating new images to upload, it is advisable to aim for an original file size of 250KB or less. Your image editor will provide far more fine tuning of compression and optimisation settings so, particularly on complex images, it is often best to use these image editing tools to “manually” fine tune the image file size to get an optimum balance of image clarity and image file size.
If you’re not able to manually achieve an original image file size of less than 250KB, don’t worry overly. Just get the image as close to 250KB as possible. As mentioned, features built into your website and the aento web hosting CDN will automatically perform image optimisation on all images uploaded.