Tumblr recently upgraded the size of images that can be used to 1MB. That means longer animated GIFs can be used to grab the reader’s attention. Animated GIFs can be created using a number of tools, such as Adobe’s Photoshop. To add them to a Tumblr post, they must be hosted by an external site such as Flickr, Imgur.com or Twitpic. Next, start a Text post. Then click Insert Image and paste in the URL for the image’s location. To see it in action, click Insert > Publish.