Toggle Element State with Google Chrome and Mozilla Firefox
It's much easier to debug CSS than JavaScript since there are many fewer interactions in CSS, and they are much easier emulate. Still, element state debugging isn't simple...until now. Google Chrome's WebInspector and Mozilla Firefox's Firebug have a really sweet feature I just discovered which allows the developer to apply element states for the sake of debugging.
Chrome's WebInspector

The image above displays Chrome's "Toggle Element State" button, allowing developers to toggle CSS states via checkboxes.
Firefox's Firebug

The image displays Firebug's likewise menu, triggered by the down arrow on the CSS tab for an element.
This allows active CSS state bugging vs. simple CSS explorations to be much, much easier. Happy CSS debugging!
![Responsive and Infinitely Scalable JS Animations]()
Back in late 2012 it was not easy to find open source projects using requestAnimationFrame() - this is the hook that allows Javascript code to synchronize with a web browser's native paint loop. Animations using this method can run at 60 fps and deliver fantastic...
![Serving Fonts from CDN]()
For maximum performance, we all know we must put our assets on CDN (another domain). Along with those assets are custom web fonts. Unfortunately custom web fonts via CDN (or any cross-domain font request) don't work in Firefox or Internet Explorer (correctly so, by spec) though...
![9 Mind-Blowing Canvas Demos]()
The <canvas> element has been a revelation for the visual experts among our ranks. Canvas provides the means for incredible and efficient animations with the added bonus of no Flash; these developers can flash their awesome JavaScript skills instead. Here are nine unbelievable canvas demos that...
![Making the Firefox Logo from HTML]()
When each new t-shirt means staving off laundry for yet another day, swag quickly becomes the most coveted perk at any tech company. Mozilla WebDev had pretty much everything going for it: brilliant people, interesting problems, awesome office. Everything except a t-shirt.
That had to change.
The basic...
Great tip, thanks =)
FireBug does this for years. Just click the little arrow next to the style tab. It’s only
:hoverand:active, though.Awesome, just added that as well.
The only thing Chrome cant do with states is when I need to debug an element that matches selector
parentElement:hover element, for exampleChrome applies states only to selected element in inspector and when you selected another element, selected state is applied to new element
Next challenge: Debug pseudo elements with web inspector :p
the Chrome web inspector already supports pseudo elements.
Under the Matched CSS rules is a Psuedo element
I believe the latest version of firebug does similar, but I’m not sure as I haven’t used it in ages
Unfortunately you can not select the pseudo element like any other DOM-Element. Technically this is perfectly valid since pseudo-elements are not part of the DOM but I often miss that feature. Pseudo-elements are harder to debug than necessary.
Good stuff, from what I know this has been around for a while already.
@JAN BECK – not that hard really, you just have to select the main element and scroll down in the inspector panel to see the psuedo elements
it’s also possible to do this with Firefox’ built in developer tools :-)