Firefox add-on: Web Developer (various web tools)

[RonnyK]

For those interested, I don't know if this was known to all, it was new for me.

This extensions makes it possible to hover over a page in FF and see what part of the CSS styles the part of the page the cursor is on.

Through "CSS -> View Style Information" a bar is visible that shows information on the active CSS.

https://addons.mozilla.org/firefox/60/

Ronny

[cyberman]

Here's a small collection of extension which are VERY useful in daily website development for me

Colorzilla
Firebug
HTML Validator
IE Tab
MeasureIt
View Source Chart
XRay

[Hare]

My personal favourite is Web Developer. Firebug is also great.