Sometime back I used a browser (can't remember the same but it looked like Firefox) which enabled me to login to multiple accounts on the same website. Meaning, whenever you open a new tab on it, it doesn't have any cookies, saved passwords etc. For example, I open the browser. Login to Facebook with account A. Open a new tab, go to Facebook and login with account B. Open another tab, go to Facebook and login with account C. In a normal browser like Chrome, if you login to Facebook and then open another tab and go to Facebook, you're already logged in. Which light-weight browser can I use to be able to do this?