Performance and connectivity

Deal with error messages, crashing applications, connectivity issues, and slow performance.

Connection settings in Firefox

Your organization or Internet Service Provider may offer or require you to use a proxy to connect to the Internet. Learn more.

Firefox Firefox Last updated:

What do the security warning codes mean?

Firefox shows you a warning page about a potential security risk when you try to connect to a secure site but your connection is not secure.

Firefox Firefox Last updated:

Manage the devices linked to your Mozilla account

Find solutions to help you manage the devices and services connected to your Mozilla account.

Firefox, Firefox for Android, Firefox for iOS,... Firefox, Firefox for Android, Firefox for iOS, Mozilla Account Last updated:

Disable Firefox Sync

Learn how to turn off Firefox Sync if you’d like to use your Mozilla account without syncing data such as, bookmarks, history and tabs.

Firefox, Mozilla Account Firefox, Mozilla Account Last updated:

Using a Primary Password with Sync

Learn how to use Sync in Firefox with a Primary Password (formerly known as a “Master Password”) for extra protection.

Firefox Firefox Last updated:
Illustration of hands

Volunteer

Grow and share your expertise with others. Answer questions and improve our knowledge base.

Learn More