Login limit increased | (The official) Tumblr Tumblelog
We’ve just increased the number of allowed simultaneous logins from 3 to 5.This means that you can be logged into Tumblr on 5 different browsers without having to re-enter your email address and password. This is handy if you want to use a home computer, a work computer, a mobile phone, and a laptop — or if you use multiple web browsers on one computer.