I know how to edit my own posts but is there an easy way to see if another user's post has been edited?
Tumblr currently offers no direct way to see if a post by another user has been edited (which is irritating sometimes).
There is a workaround: If a post is reblogged, and the original post is then edited, the reblog will not change to reflect the changes to the original post. Because of this, you can technically compare (early) reblogs of a post to the original post to see if there are any changes. If there are, the original post has probably been edited.