Running more than one Firefox instance allows you to use multiple cookies for a website. By default, you are limited to two separate cookies through *regular* and *private* windows. Using Firefox's **profiles**, you can use more than two.
For example, you are looking for item A and B at a shopping website using the private window but you prefer to keep the browsing separate as not to let the website knows that you are browsing both of them. Or you want to login to more than two accounts of a website.
A useful feature of Firefox is that it allows more than one profile, which otherwise would requires multiple operating system accounts. The feature even allows you to run multiple profiles at the same time by having multiple instances.
7. Just launch Firefox as usual for your current profile.
## Clone profile
1. Notice the directory shown in step 4 in previous section, that is where profile(s) is stored.
2. Browse to the **~/.mozilla/firefox** folder
3. To clone the default profile, simply select the xxxx.default and duplicate it by **Edit: -> Duplicate**, or copy to another folder, rename and move it back. Rename the cloned folder to desired name. In this example, I named it as *profile z*.
Multi-Account Containers is a built-in feature introduced since Firefox 50, but disabled by default (as of Firefox 68). Follow this link [[wiki.mozilla.org]](https://wiki.mozilla.org/Security/Contextual_Identity_Project/Containers) for instruction and more details.
The feature is also available through [an add-on](https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/). The add-on offers the ability to assign a site to a specific container, so that a website will always open in a specified container.
