Firefox FAQs and troubleshooting

Enhanced Tracking Protection blocks known trackers and related tracking content while you browse. Its protections can include cross-site tracking cookies, social media trackers, fingerprinting scripts and other known tracking resources, depending on your protection level.

Some sites load login buttons, videos, payment forms or embedded content from resources that also contain trackers. Firefox can apply compatibility exceptions in limited cases, and you can temporarily disable Enhanced Tracking Protection for a specific site to test whether protection is causing the breakage.

Login failures can come from blocked cookies, stale site data, extensions, strict tracking protection or site-specific compatibility problems. Try reloading, clearing cookies and cache for that site, checking content-blocking extensions and testing the site with Enhanced Tracking Protection temporarily disabled.

Use Firefox’s Cookies and Site Data controls to remove stored data for the affected site, then reload it. Clearing site-specific cookies can fix broken login sessions, while clearing cached files can fix pages that load outdated or corrupted resources.

No. You can browse, install extensions and change Firefox settings without signing in. A Mozilla account is mainly used for Firefox Sync and other Mozilla services.

Firefox Sync can synchronize bookmarks, passwords, open tabs, browsing history, addresses, payment methods, add-ons and browser settings. You can choose which data categories you want to sync.

Yes. In Firefox Sync settings, you can enable or disable individual categories such as bookmarks, passwords, open tabs, history, payment methods, add-ons and settings.

If Sync was enabled, signing in with the same Mozilla account can bring supported synced data to the new device. You can also use Firefox backup or profile backup methods for an additional copy of bookmarks, passwords and settings.

Yes. An extension can affect page loading, memory use or browser behavior. Firefox Troubleshoot Mode temporarily disables extensions and themes so you can test whether one of them is causing the problem.

Start Firefox in Troubleshoot Mode. If the problem disappears, re-enable extensions one at a time, switch back to the default theme and test hardware acceleration until you identify the cause.

Yes. Firefox includes tab groups and vertical tabs for organizing larger browsing sessions. You can also use pinned tabs, Firefox View and the sidebar to manage open pages in different ways.

Memory use depends on the number of tabs, websites, video content, extensions and your Firefox profile. Firefox’s built-in process and performance views can help identify tabs or extensions using unusually large amounts of resources.

Restart Firefox, update it, test in Troubleshoot Mode, disable suspect extensions and check whether the slowdown happens on one website or across the browser. If the issue continues, Firefox Refresh can restore many defaults while preserving essential data.

Troubleshoot Mode starts Firefox with extensions and themes disabled and with some hardware-related settings temporarily changed. It is designed to help determine whether customization is causing crashes, slowness or display problems.

Refresh Firefox restores many browser settings to their defaults and removes add-ons and customizations while keeping essential personal information such as bookmarks, browsing history and saved passwords.

Differences can come from site code, browser-specific assumptions, extensions, cached files or privacy protections. Update Firefox, reload without cache, test extensions and check whether the site works when Enhanced Tracking Protection is temporarily disabled.

Check whether the site works in another browser or device, confirm your network connection and DNS behavior, then review Firefox proxy or connection settings. Security software or a misconfigured proxy can also block requests.

Firefox blocks a connection when it cannot establish a trusted secure session. The cause may be an invalid site certificate, incorrect system time, security software intercepting HTTPS, a captive portal or a network configuration problem.

They can in some cases because third-party resources may contain both necessary site functionality and tracking code. Firefox uses web-compatibility exceptions in limited cases, and you can test a site by temporarily disabling Enhanced Tracking Protection for that domain.

Yes. Firefox can import bookmarks, saved passwords, browsing history and other supported preferences from Chrome without removing Chrome or changing its settings.

Firefox supports local backup and profile backup options in addition to Sync. A Firefox backup file can store profile data such as bookmarks, settings and passwords, and manual profile copies provide another recovery path.

Yes. Firefox automatically creates bookmark backups, and you can also save your own bookmark backup files. Those backups can be restored on the same computer or moved to another Firefox profile.

Often, yes. If Sync was enabled, signing back in can restore supported synced data. If your old Firefox profile or a backup file still exists, you may also be able to recover bookmarks, passwords, history and settings from it.

Update Firefox, restart it and check whether the problem affects one site or the whole browser. Then test Troubleshoot Mode, clear site data where relevant and disable recent extensions or customizations.

A new profile is useful when the problem continues after normal troubleshooting or Firefox Refresh. It gives you a clean browser profile without your old extensions and custom settings, which helps confirm whether the existing profile is damaged.

Use Mozilla Support for current troubleshooting articles, product-specific help and community support. For repeatable website compatibility problems, Firefox also provides a broken-site reporting path to the Webcompat team.

Yes. An account is optional. You can browse, install extensions, and adjust settings without signing in; the account mainly adds sync and related services.