extract Critical CSS rules for the current page
Once you install this extension, you will see a new panel, 'Critical CSS' in your Developer Tool. By clicking 'Extract Critical CSS', a text file which has CSS rules for Above the Fold, or First View of a current page is downloaded.
fix for getting url command
fix format in downloaded file
fix for root relative path
support for @support
fix for CSSMediaRule
fix handling of @import rule
fix to duplicate a current tab even if a devtool floats
fix for webkit pseudo elements
open original page in new tab
add preference page
preserve back slashes in css rules
prevent css rules of different frames from applied to a main frame
fix for pseudo elements and pseudo classes.