I'm surprised this one is not built-in in Firefox. For daily front-end developer it is a must have.

love it, just what i was looking for for doing frontend dev.

The only extensions that works perfect for measuring others suck

Works great! Exactly the functionality missing from other Add-ons.

Great, Gives exact size of each html element used

It took just a little time to get used to this tool. Now, it's really convenient to measure everything, at least what I needed to measure!

Can't select inside iframes. Apart from that, this extension is priceless. It's incredibly helpful and I use it almost anytime I have to do a requirement about a graphical interface.

Did work as expected. The only thing I would recommend is to exit extension mode by using ESC key.

Possibly my favourite addon (with TabStash)! It's very efficient in measuring against a design (like Figma)or simplifying layout.

Exactly what a web dev needs!!!