When adding a featured image to each blog post here is what you want to consider when it comes to size.
The "Featured Image" you add to each blog post is used for multiple purposes. Let's cover a few of those here:
- It's the key image at the top of the post
- It's used as a thumbnail on the blog listing page or throughout the website
- Social sharing image across various networks
Optimize the featured image for social sharing.
Of the three purposes I mentioned above, social sharing is likely this image's most important job to consider. Here's the rub... Each social network utilizes a different size.
- Twitter has a 2:1 ratio and suggests a 1024 x 512 pixel image
- The 2:1 ratio is not quite accurate on Twitter’s iOS mobile app; images are cropped more significantly on the left and right borders and are displayed at a 1.75:1 ratio
- Facebook suggests a 1200 x 630 pixel image
- LinkedIn posts a thumbnail-sized image at 180 x 110 pixels
How's that for confusing?
When in doubt, go with a 16:9 ratio (1600 x 900px).
Your best be when selecting a size that will work across all the platforms is the 16:9 ratio. Some of the edges may get cropped out depending on the platform is shared on so if you happen to have text in the image (which I don't recommend) you'll want to make sure there is ample space on both sides.