Did you hear about this: New Facebook Cover Image Rule Limits Text to 20 Per Cent (20%)? In 2013, Facebook quietly announced that their new Facebook Cover Image rule limits the amount of text you can have in your cover image to 20% or less.
Use this link to see if your Facebook Cover Image is violating the 20% rule or not. Simply upload your image.
You’ll be given a message as to whether or not you’re in violation of Facebook’s new rule about cover images and text.
Example: I uploaded this image: 
…and was told:
You may not reach your audience because there’s too much text in the ad image. Facebook prefers ad images with little or no text. Unless you qualify for an exception, change your image before placing your order.
To be clear: if you’re not going to pay Facebook to boost your post or do an ad campaign, you can use more than 20% text overlaid onto your image.
