How to log Into several Gmail Accounts at the same time on Mozilla Firefox? How to run multiple instances of Mozilla Firefox simultaneously?

With general settings you cannot log into more than one Gmail accounts on Mozilla Firefox browser simultaneously. The reason is, GMail uses cookies for authentication and tracking the state of the user. So, whether you open a tab or a new window of Firefox, GMail cookie is shared between them, because all these are part of the default instance.

The solution is to create a new instance of the Firefox. Following steps can be followed to run multiple instances of Firefox at the same time:

For Linux based Computers

1. Open terminal and run command:

firefox -no-remote -ProgramManager

2. The Firefox program manager will pop-up and ask you to create or use the existing Profile. If you have got only Default Profile, then click on the “Create Profile” button to create a new profile and once it is created, select it and click “Start Firefox”

For Windows based Computers

1. Open command prompt run command:

firefox.exe -no-remote -ProfileManager




2. The Firefox program manager will pop-up and ask you to create or use the existing Profile. If you have got only Default Profile, then click on the “Create Profile” button to create a new profile and once it is created, select it and click “Start Firefox”