Hard to tell in your photos and the only definite way is to do a scale count but there is a fairly sure way to tell the difference between a taipan and browns. The brown snake's neck follows cleanly through to the head while the Taipan has a slightly narrowed neck. But the biggest difference is the Taipan has a longish angular head shaped like a coffin and the tip of the snout is a lighter colour, often pinkish.
http://www.animalpicturesarchive.com...is_Desmond.jpg
Either way, steer well clear of both of them.