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Enhanced Tracking Protection in Firefox automatically protects your privacy while you browse.
Firefox automatically updates itself by default, but you can always do a manual update. Learn how to update Firefox on Windows, Mac, or Linux.
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.
The Send Tab feature lets you send pages from Firefox desktop to your phone or tablet so you can view them later.