In February, we announced that images with 1.91:1 aspect ratios could be used with website cards. Starting today, website cards can be created using 1:1 images.
These images must be at least 800px wide and 800px tall. In the response, both the
image_display_width and the
image_display_height—the display dimensions—will be
With this addition, we will be transitioning away from the 5:2 aspect ratio. As early as 2017-10-01, we will no longer allow website cards to be created using 5:2 images.
Twitter Ads API Team