How to load default image on Twitter?

Question

On Twitter, if the image is not loaded, a default image will be displayed. I checked that this is not the background image in the background-image attribute, but img## Pictures introduced with the #tag.

The question is, how does Twitter determine that the image that should be displayed failed to load?

Answer 1

You should check out Twitter’s developer API. There should be an introduction in it

Answer 2

You can use the onerror event of the img tag