Evernote Web Clipper - if the extension is already installed in the browser, button will be automatically converted to gray and will be disabled
/via Art Revolt
theyouway.com - When opening a new tab the page title changes to “♥ Come back luv!”.
/via Daniel Lindholm
37 Signals - Blog post header text changes with size by dropping non-essential words as the browser viewport gets smaller.
/via Razvan Caliman
Amazon - After completing your order, the page title changes to: “Amazon.com Thanks You”
/via Steven Scarborough
Github - The private label of Github adjusts its angle with an animation to fit your browser window.
Firefox - The ‘forward’ button slides in only after going back to a previous page.
/via Alexander Solovyov
Google Docs - Pressing ⌘+s (ctrl + s) the first time will save the document in the interface, while pressing it again will open the default browser dialog to save the page to your hard drive.
/via Gregory Koberger
Chrome - When uploading files, the usual blue rotating circle in the tab bar becomes gray and spins counterclock-wise.
/via Julian Peters
Firefox - If you start typing a URL and you already have a tab open of that URL, the first option in the dropdown offers to switch you to that tab.