The Hootsuite Composer displays a preview of your post, for each social network, while you’re crafting it. As you add to your post, previews update in real time so you can see what your audience will see.
While previews are as accurate as possible, some elements only get finalized by the social network when a post is published. This can result in minor differences between the preview and final post.
Link previews, for example, generate automatically, but each social network pulls link preview information differently from the link’s website. This means that the resulting link preview for a given link may not be the same on each social network.
See Link previews and troubleshooting to understand link preview results on each social network.
Images can also publish with different results depending on the social network.
Maximum file size (5MB, and 3MB for Twitter), and aspect ratio for Instagram (between 1.91:1 and 4:5) are the only requirements for image files. Besides these, social networks accommodate image uploads in a wide range of dimensions and resolutions. This is because each social network performs its own optimization on images.
Images are optimized to look their best on each platform. Adjustments are made to best support fitting the allotted space, rendering the image in multiple sizes, and displaying it optimally on all devices and screens.
Optimization methods are continually being tested by the social networks, but can include resizing, reformatting, scaling, and cropping. Because of this automatic image optimization, we recommend keeping any overlaid text away from the edges of your images.
If your image is published with unwanted adjustments, refer to the image upload recommendations from each social network: