Is there any way to undo upvotes for comments, like upvotes and downvotes for normal questions and answers?
No, it is not possible to undo an upvote that is done to a comment.
The request to allow this functionality is also declined. Comment upvotes are very minor in impact in the grand scheme of things, they don't even affect reputation. As such, the need for reversing an upvote is very minor.
status-completed - As of April 2012 - It is possible to undo comment upvotes (some limitations apply - the primary use case is to undo an accidental click). According to waffles, former employee at Stack Exchange:
- You can un-upvote a comment within the first 60 seconds, provided you did not navigate away.
- Once you un-upvote a comment you can not upvote it again.
We do not want flip flopping, nor do we want people to un-upvote stuff from the past. The only use case is undoing a mis-click.
Here's what it looks like when you start to unupvote a comment:
Then if you try to upvote the same comment again: