Inspect Shadow DOM with Firefox
Type about:config in the browser address bar. Set devtools.inspector.showUserAgentShadowRoots to true // not needed for Firefox 76+ Set devtools.inspector.showAllAnonymousContent to true (Firefox 76+)
firefox
How to find xpath of an element in firefox inspector
You can use the console to check if the xpath you want return the correct element or not. $x(“//div/xpath”) https://developer.mozilla.org/en-US/docs/Tools/Settings
What to do about “The Components object is deprecated. It will soon be removed.” in dev tools Console
This is not for the developer of the page to solve. While biking back home, a possible cause popped up in my mind: could one of the add-ons I use cause this and yes, that appears to be the case. I restarted with disabled add-ons and the message was gone. Then I enabled them one … Read more
How can I have multiple rows with tabs on Firefox 57+ (Add-on “Tab Mix Plus” no longer works)?
Multirow tab bar with working tab dragging (tested on FF 61): Download and extract https://luke-baker.github.io/Firefox_chrome.zip Copy userChrome.xml to your chrome folder. Add content from userChrome.css to your userChrome.css. Download MultiRowTabLiteforFx.uc.js to your chrome folder. Your chrome folder is a folder named chrome located under your user profile, e.g. ~/.mozilla/firefox/g7fa61h3.default/chrome. It does not exist by default, … Read more
Firefox -moz-border-radius won’t crop out image?
Workaround: Set the image as the background of a container element, then add border radius on that element.
Simulate Offline Mode for HTML5 Cache Testing
For Firefox ☰ (hamburger menu)->More->Work Offline Google Chrome doesn’t appear to have this feature Edit: Also, another alternative is slightly more time-consuming to setup in the beginning but might be worth it. For Firefox/Chrome there should be proxy plugins, set up a fake/bad profile for each so that you proxy to something that doesn’t exist… … Read more
The character encoding of the plain text document was not declared – mootool script
In your HTML it is a good pratice to provide the encoding like using the following meta like this for example: <meta http-equiv=”content-type” content=”text/html; charset=utf-8″ /> Note: if any line between <head> and this meta line (Even if it’s a commented note) problem will remain, so make sure you added meta line after <head> directly … Read more
Can Firefox’s “view source” be set to not make a new GET request?
If you install the web developer toolbar extension, there’s an option under “View Source” called “View Generated Source” which will show you the current source of the page, including any DOM changes you may have made.
Firefox printing only 1st page
I just found out, that from an element with display:inline-block; only the first page is printed and everthing else is hidden. setting this to display:block; was the solution in my case.
Way in Firefox to show current window dimensions? [closed]
I know this is a 4 year old answer, but I don’t see anyone mention that you just have to select the toggle rulers option. Go to the settings menu option in the developer tools and check it. That will bring up the ruler icon and just click it and you have your ruler.