Advanced Settings :: Privacy Settings
0: Never send the referring URL (maximum privacy; breaks some sites)
1: Send only when links are clicked
2: Send for links and images (default)
0: Always send referrer (default)
1: Only send if base domains match
2: Only send if hosts match
0: Send full URI (default)
1: Scheme, host, port and path
2: Scheme, host and port
0: All cookies are allowed (default)
1: Only cookies from the originating server are allowed
2: No cookies are allowed
3: Third-party cookies are allowed only if that site has stored cookies already from a previous visit
0: The cookie's lifetime is supplied by the server (default)
1: The user is prompted for the cookie's lifetime
2: The cookie expires at the end of the session (when the browser closes)
3: The cookie lasts for the number of days specified by network.cookie.lifetime.days
true: Spoof the referrer and use the target URI instead
false: Send the referrer (default)
true: May leak information to third-party sites through Firefox's Network Prediction features (default)
false: Prevents leaking information to third-party sites through Firefox's Network Prediction features
true: Third-party cookies are allowed within the limits of the general cookie acceptance settings but only retained for the current session
false: Third-party cookies are allowed within the limits of the general cookie acceptance and retention settings (default)
true: Allow Firefox to handle Captive Portals (a router man-in-the-middle that intercepts page load) (default)
false: Disables handling of Captive Portals in Firefox (a router man-in-the-middle that intercepts page load)
true: Retrieve and display search term suggestions for search plugins that support it (default)
false: Disable search suggestions
true: Automatically copy contents of selections to the clipboard (default in Linux)
false: Do not auto-copy selections (default everywhere else)
true: Allow Firefox Hello to log domains (default)
false: Disable domain logging if Firefox Hello is not entirely disabled
true: Enables application reputation checks for downloaded files (default)
false: Disables application reputation checks for downloaded files (it is recommended to disable browser.safebrowsing.downloads.remote.enabled from the main panel instead)
true: Enable OCSP stapling (default)
false: Disable OCSP stapling
true: Website owners (not the issuing CA) respond to the OCSP queries
false: Issuing CA respond to the OCSP queries
true: Check for certificate revocations (may break some websites like YouTube)
false: Do not check for certificate revocations (default)
0: Do not query OCSP from the responder server
1: Validate only certificates that specify an OCSP service URL (default)
2: Enable and use values in security.OCSP.URL and security.OCSP.signing
false: Firefox is started normally (default)
true: Private Browsing mode is used automatically.
false: Scripts may only close windows opened by scripts (default)
true: Scripts may close any window
false: The popup blocker is disabled
true: The popup blocker is enabled (default)
false: Web pages won't be allowed to manipulate or block the context menu
true: Websites may manipulate the context menu (default)
0: Never use document's fonts (set "gfx.downloadable_fonts.enabled" to true to block regular fonts, but allow downloading of glyphs/icon-fonts)
1: Allow documents to specify fonts to use (default)
2: Always use document's fonts (deprecated)
false: Disable glyphs/icon-fonts (will cause the extension to not display icons)
true: Enable glyphs/icon-fonts (set browser.display.use_document_fonts to 0 to block regular fonts, but allow downloading of glyphs/icon-fonts)(default)
false: Disable CSS engine from blending element's content with the content of the element that is below it
true: Enable CSS engine to blend element's content with the content of the element that is below it (can reveal browser's history)
false: Perform DNS prefetching (default)
true: Disable DNS prefetching
false: Disable link prefetching
true: Enable link prefetching (default)
false: Disable Pocket Integration
true: Allow Pocket Integration (A third-party service for managing a reading list of articles)
false: Disable media device enumeration
true: Enable media device enumeration. This exposes unique identifiers of all audio/video devices (default)
false: Enable page thumbnail collection (default)
true: Disable page thumbnail collection (look in profile/thumbnails directory - you may want to clean that out)
0: no-referrer
1: same-origin
2: strict-origin-when-cross-origin
3: no-referrer-when-downgrade (default)
Recommended value: true (Disabling may slow-down your browsing)
more info
Prevent Firefox from making connections when you hover over links in the browser
Recommended value: 0
more info