Performance and connectivity

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

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:

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:

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: 1 week, 1 day ago

Resist Fingerprinting

Firefox's Advanced Preferences to resist fingerprinting can help prevent websites from uniquely identifying your device but can cause problems. Learn more.

Firefox Firefox Last updated: 2 weeks, 3 days ago

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:

RCS messaging and Mozilla VPN

RCS (Rich Communication Services) messaging on iOS 18 does not work when using Mozilla VPN. Learn how to fix or work around this issue.

Mozilla VPN Mozilla VPN Last updated:

Firefox DNS over HTTPS

DoH improves privacy by hiding domain name lookups from anyone lurking on public Wi-Fi, your ISP or others on your local network. Learn more.

Firefox Firefox Last updated: 1 week ago

DNS over HTTPS (DoH) FAQs

We have outlined a list of FAQs here that you may find helpful while getting up to speed with all that DNS over HTTPS (DoH) has to offer.

Firefox Firefox Last updated: 1 week ago

How to obtain the Mozilla VPN Logs

When troubleshooting issues with Mozilla VPN, our engineers can ask for logs. These don't contain any personal information, but give hints about the issue.

Mozilla VPN Mozilla VPN Last updated:

Firefox for iOS won't load web pages

If a website isn’t loading even after you’ve checked the Internet connection, here are a few things you can try.

Firefox for iOS Firefox for iOS Last updated:
Illustration of hands

Volunteer

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

Learn More