Online tool or browser addon to show div's in different colors

[bolshi]

Hi.

The last days I spent a lot of time finding a bug in a website I develop for my school. There was a div which overlapped another.

Do you know a tool or browser addon which makes div blocks visible in different colors or shows them with borders?

 

 

[dsonesuk]

Usually a decent editor would highlight something like this, it would give you the ability to collapse these containers to identify misplaced  opening or closing tags. You  can also use W3C html validator.