Nowadays, Mozilla Firefox is available on almost all platforms, whether traditional platforms (Windows, Mac…) or mobile platforms. Since a person can now have Firefox on several of their devices, it would be really handy to be able to share their settings between all of their browsers. This is where Firefox Sync comes in. Indeed, the latter allows you to share your bookmarks, browsing history and much more between the different versions of Mozilla Firefox installed on different devices.
Steps
Part 1 of 2: set up the first device

Step 1. Open Mozilla Firefox
Double-click the icon on your desktop to open the browser.

Step 2. Open the Options window
Click on Tools in the menu bar at the top of your browser window then select Options.

Step 3. Click the Sync tab

Step 4. Log in to your Firefox account
Enter your username and password in the fields provided. Then click on Log in.
- If you do not yet have a Firefox account, you can create one by clicking on the link Create an account which is in the tab Sync. All you have to do is fill in the different fields of the form to create your account.

Step 5. Click Manage
After signing in, you will be automatically redirected to the Firefox Sync home page. Click on the button Management to open the Options window and start managing your information.

Step 6. Configure the device
In the Options window, select the set of browser data that you want to share between your devices. Then enter a name that will identify your device (for example: "Home computer").
Each of your Firefox browsers will have its own name

Step 7. Click OK to save your settings
Your browser data is now ready to sync with another device.
Part 2 of 2: Synchronize Your Browser Data with a Second Device

Step 1. Open Firefox on your smartphone
Tap the icon on your home screen to launch the app.

Step 2. Then go to Settings
Open your browser menu then select Settings.

Step 3. Tap Sync
On the Settings page, tap Sync. You will then receive a code consisting of 9 to 12 characters.

Step 4. Go back to your first device
Open the window Options and go to the tab Sync (2nd and 3rd steps of the "Configure the first device" part).

Step 5. Click Add Device

Step 6. Enter the code in the field provided
Enter the alphanumeric code that you obtained on your second device then click on To end in order to synchronize.