Get Help
Pick your product
Firefox
Web browser for Windows, Mac and Linux
Firefox for Android
Web browser for Android smartphones and tablets
Firefox for iOS
Firefox for iPhone, iPad and iPod touch devices
Mozilla VPN
VPN for Windows 10, Mac, Linux, Android, and iOS devices
Firefox Relay
Service that lets you create email masks to hide your real email address
Mozilla Monitor
Find out if your private information has been exposed in a known data breach
Discover and save stories for later
MDN Plus
MDN Plus provides a custom user experience for MDN supporters
Firefox Focus
Automatic privacy browser and content blocker
Firefox for Enterprise
Firefox Quantum for businesses
Thunderbird
Email software for Windows, Mac and Linux
Thunderbird for Android
Email app for Android smartphones and tablets
Featured Articles
Insecure connection password warning in Firefox
Firefox will show you a "connection is not secure" warning message when a website login page is insecure and information could be stolen.
Common Myths about Private Browsing
Learn more about common misconceptions about Private Browsing in Firefox.
Get community support
Learn how to connect with the Mozilla community to ask questions and find solutions from fellow users.
How to troubleshoot security error codes on secure websites
Learn about the error codes SEC_ERROR_UNKNOWN_ISSUER MOZILLA_PKIX_ERROR_MITM_DETECTED and ERROR_SELF_SIGNED_CERT on HTTPS websites and how to troubleshoot.
Join Our Community
Grow and share your expertise with others. Answer questions and improve our knowledge base.