Twitter的cover图片尺寸是多大？

Twitter建议的是1500 * 500，
但合适的是：
1500 x 421像素。

Twitter官方英文解释：

The Twitter header size is 1252x626px.

Twitter’s recommended dimensions for header photo is 1500px in width X 500px in height. But the size that really works well for me is (which I’m currently using):
1500px (width) X 421px (height)
But you need the template to make this WORK for you…Read on.