I have included both the desktop version and the mobile version to compare the features. Although I am personally a fan of Opera, Firefox wins in the end as the browser with the most features. Second place goes to Opera, followed by Chrome and Edge. Safari is the worst browser in terms of features, both on Mac OS X and on mobile devices (iOS).
If you spot any errors (or any new features were created), please leave a comment.
Download/Fullsize (external link)