Firefox/Chrome add-on for pixel-by-pixel reconciliation with the layout

Question

Google Chrome

Hello.
I remember that about four years ago, information periodically flashed about a plug-in for Firefox, which superimposed a translucent layout of the same site on top of the site so that you could check the arrangement of elements pixel by pixel.
Do not tell me the name of the plugin or any other approach to solving the problem, other than using a modular grid or rulers.

Answer 1

pixelperfectplugin.com/

Answer 2

When there is nothing to complain about, but you really want to, pixel hunting begins ... And this is the very awkward moment when the layout designer begins to think about suicide.

Answer 3

PixelPerfect for FF
Analog for Chome