Don't convert an upvote to a downvote

I would suggest it should be more prominent that you have previously voted. If the upvote icon changed colour or was more prominent, you would easily see that you have already voted. You are then less likely to cast your vote again.

But there still needs to be a way to reverse your vote. If the upvote button is indicating that I have previously voted, I do not see a problem with clicking it again to reverse that, I believe that clicking the upvote again is more natural to reverse the vote than clicking the downvote icon.

So, I see two issues with the vote icons. Knowing that you have previously voted and action for reversing a vote.

How would you prefer to reverse your vote?

When you upvote, the icon changes but when you refresh the window or check the post again, you don't have any way of knowing if you have upvoted the feature previously.

You see the vote count drops when you upvote the feature again by clicking on the upvote button.

Team Diziana

Great additions @... and @....  If I had known I'd already upvoted the post, I wouldn't have tried to upvote again in the first place and potentially cancelled out my vote. 

If I think through how I would probably expect to cancel out my vote on other sites, I would click the upvote arrow again to cancel the vote - but other sites are more clear about current upvote state.  Typically the vote arrows are bolded or colored to indicate a selection and dull to indicate no selection.  

Maybe the better recommendation here is to make your votes on a post more prominent so you know your current vote status.