Mozilla Firefox
What the default settings do
Firefox ships with Enhanced Tracking Protection set to Standard by default, which blocks known third-party trackers, cryptominers, and fingerprinters. Firefox also collects some telemetry data and sends it to Mozilla, including technical interaction data and crash reports.
Several features are enabled by default that connect to Mozilla and partner services, such as Pocket recommendations on the new tab page, Firefox Suggest in the address bar, and periodic data collection for product improvement.
A reasonable privacy baseline
These settings are found in Settings → Privacy & Security from the Firefox menu.
Enhanced Tracking Protection
Enhanced Tracking Protection → Strict
Standard mode blocks known trackers, cryptominers, and fingerprinters. Strict mode adds cross-site cookie isolation and blocks tracking content in all windows (not just private windows). This provides stronger protection with a modest increase in site breakage.
Cookies and Site Data → Delete cookies and site data when Firefox is closed → Consider On
Clears cookies when you close Firefox. This limits long-term tracking but means you will be logged out of all sites each session. You can add exceptions for sites where you want to stay signed in.
Firefox Data Collection and Use
Allow Firefox to send technical and interaction data to Mozilla → Off
This sends telemetry data about how you use Firefox, including feature usage, performance, and hardware configuration. Turning it off stops this collection.
Allow Firefox to send backlogged crash reports on your behalf → Off
When enabled, Firefox automatically sends previously unsent crash reports to Mozilla. Turning this off means crash reports are only sent when you explicitly choose to submit them.
Allow Firefox to install and run studies → Off
Mozilla occasionally runs studies that install temporary extensions or change settings to test new features. Turning this off opts you out of these experiments.
Address Bar - Firefox Suggest
Suggestions from Firefox → Off
Firefox Suggest sends your keystrokes to Mozilla's servers to provide contextual suggestions including results from partners. Turning this off keeps address bar suggestions local to your bookmarks, history, and open tabs.
Suggestions from sponsors → Off
Disables sponsored suggestions in the address bar that are served based on what you type.
New Tab Page
Pocket Recommendations → Off
The new tab page shows article recommendations from Pocket (owned by Mozilla). These are not personalized by default, but turning them off removes the feature and its associated network requests.
Sponsored content on new tab → Off
Removes sponsored tiles and stories from the new tab page.
DNS over HTTPS
DNS over HTTPS → Max Protection or Increased Protection
Firefox can encrypt DNS queries so your internet provider cannot see which domains you look up. "Max Protection" sends all DNS queries through the encrypted resolver and fails if the resolver is unreachable. "Increased Protection" falls back to your system DNS if the encrypted resolver fails. The default resolver is Cloudflare, which can be changed.
Permissions
Permissions → Location, Camera, Microphone, Notifications → Review and consider Block new requests
By default, Firefox asks each time a site requests access. You can preemptively block all new requests for each permission type and add exceptions only for sites you trust. This prevents unexpected permission prompts.
Trade-offs
- Strict Enhanced Tracking Protection may cause some websites to display incorrectly or lose functionality, particularly sites that rely on cross-site cookies for login or embedded content. You can disable protection for individual sites if needed.
- Deleting cookies on close means re-authenticating with every browser session. Adding exceptions for frequently used sites reduces friction.
- Turning off telemetry means Mozilla receives less data to identify and fix issues. Mozilla uses this data to improve Firefox and measure feature adoption.
- Disabling Firefox Suggest and Pocket removes features some people find useful for content discovery. Address bar results will be limited to your own browsing data.
- DNS over HTTPS in Max Protection mode may cause issues on networks that require specific DNS configurations, such as corporate or school networks with internal domains.
- Blocking all new permission requests means you will need to manually add exceptions when a legitimate site needs camera, microphone, or location access.
Who should not change these settings
- If you use a corporate or school network with custom DNS requirements, DNS over HTTPS may interfere with internal site resolution. Your IT department may require this to be off or set to a specific resolver.
- If you find Pocket recommendations useful for discovering articles, leaving them on is reasonable since they are not individually targeted by default.
- If you want to help Mozilla improve Firefox and are comfortable with the telemetry collected, leaving data collection on supports an independent browser project.
- If Strict tracking protection breaks sites you use regularly and managing per-site exceptions feels burdensome, Standard mode is already a meaningful level of protection.
- If you prefer staying logged in across browser restarts, do not enable the setting to delete cookies on close, or carefully maintain your exceptions list.