flags.md

List of flags and switches

This is an exhaustive list of command-line switches and flags introduced by ungoogled-chromium. Each switch has a corresponding entry on the chrome://flags page which can be filtered by searching for ungoogled-chromium.

If a switch requires a value, you must specify it with an = sign; e.g. flag --foo with value bar should be written as --foo=bar.

NOTE: If you add a command-line argument that is also in chrome://flags, the flag's state will not be indicated in chrome://flags. There is no universal way to ensure command-line flags are taking effect, but you can find if they're being seen by checking chrome://version.

• Available on all platforms

  Switch	Description
  --disable-beforeunload	Disables JavaScript dialog boxes triggered by beforeunload
  --disable-grease-tls	Disables GREASE for TLS. Combined with --http-accept-header allows browser to look more like a tor-browser. See ungoogled-software#783 for more details.
  --disable-search-engine-collection	Disable automatic search engine scraping from webpages.
  --extension-mime-request-handling	Change how extension MIME types (CRX and user scripts) are handled. Acceptable values are download-as-regular-file or always-prompt-for-install. Leave unset to use normal behavior.
  --fingerprinting-canvas-image-data-noise	(Added flag to Bromite feature) Implements fingerprinting deception for Canvas image data retrieved via JS APIs. In the data, at most 10 pixels are slightly modified.
  --fingerprinting-canvas-measuretext-noise	(Added flag to Bromite feature) Scale the output values of Canvas::measureText() with a randomly selected factor in the range -0.0003% to 0.0003%, which are recomputed on every document initialization.
  --fingerprinting-client-rects-noise	(Added flag to Bromite feature) Implements fingerprinting deception of JS APIs getClientRects() and getBoundingClientRect() by scaling their output values with a random factor in the range -0.0003% to 0.0003%, which are recomputed for every document instantiation.
  --force-punycode-hostnames	Convert all Internationalized Domain Names to punycode (ASCII representation of Unicode). See ungoogled-software#370 for more details.
  --hide-crashed-bubble	Hides the bubble box with the message "Restore Pages? Chromium didn't shut down correctly." that shows on startup after the browser did not exit cleanly.
  --http-accept-header	Changes the default value of the Accept HTTP header sent with HTTP requests. Combined with --disable-grease-tls allows browser to look more like a tor-browser. See ungoogled-software#783 for more details.
  --keep-old-history	Disables deletion of local browser history after 90 days
  --max-connections-per-host	(from Bromite) Configure the maximum allowed connections per host. Valid values are 6 and 15
  --omnibox-autocomplete-filtering	Restrict omnibox autocomplete results to a combination of search suggestions (if enabled), bookmarks, and internal chrome pages. Accepts search, search-bookmarks, search-chrome, and search-bookmarks-chrome.
  --popups-to-tabs	Makes popups open in new tabs.

• Available only on desktop

  Switch	Description
  --bookmark-bar-ntp	Sets the visibility of the bookmark bar on the New Tab Page. Only takes the value never.
  --close-confirmation	Show a warning prompt when closing the browser window. Accepts last (prompt when closing the last window with several tabs) and multiple (prompt only if more than one window is open).
  --close-window-with-last-tab	Determines whether a window should close once the last tab is closed. Only takes the value never.
  --custom-ntp	Allows setting a custom URL for the new tab page. Value can be internal (e.g. about:blank or chrome://new-tab-page), external (e.g. example.com), or local (e.g. file:///tmp/startpage.html). This applies for incognito windows as well when not set to a chrome:// internal page.
  --disable-sharing-hub	Disables the sharing hub button.
  --enable-incognito-themes	Allows themes to change the appearance of Incognito windows.
  --hide-extensions-menu	Hides the extensions container. This includes the puzzle piece icon as well as any pinned extensions.
  --hide-fullscreen-exit-ui	Hides the "X" that appears when the mouse cursor is moved towards the top of the window in fullscreen mode. Additionally, this hides the "Press F11 to exit full screen" popup.
  --hide-tab-close-buttons	Hides the close buttons on tabs.
  --remove-grab-handle	Removes the reserved empty space in the tabstrip for moving the window.
  --remove-tabsearch-button	Removes the tabsearch button from the tabstrip.
  --scroll-tabs	Determines if scrolling will cause a switch to a neighboring tab if the cursor hovers over the tabs, or the empty space beside the tabs. The flag requires one the values: always, never, incognito-and-guest. When omitted, the default is to use platform-specific behavior, which is currently enabled only on desktop Linux.
  --show-avatar-button	Sets visibility of the avatar button. The flag requires one of the values: always, incognito-and-guest (only show Incognito or Guest modes), or never.
  --tab-hover-cards	Allows removing the tab hover cards or using a tooltip as a replacement. This can be set with the values none or tooltip.

  • Available only on Windows

    Switch	Description
    --disable-encryption	Disable encryption of cookies, passwords, and settings which uses a generated machine-specific encryption key. This is used to enable portable user data directories.
    --disable-machine-id	Disables use of a generated machine-specific ID to lock the user data directory to that machine. This is used to enable portable user data directories.

Feature flags

Feature flags are similar to switches with the difference being that they are passed as values for the --enable-features switch. Multiple features can be passed at the same time by separating them with a comma, e.g. --enable-features=flag1,flag2,flag3. These are also available on the chrome://flags page.

• Available on all platforms

  Feature	Description
  MinimalReferrers	Removes all cross-origin referrers and strips same-origin referrers down to the origin. Has lower precedence than NoCrossOriginReferrers.
  NoCrossOriginReferrers	Removes all cross-origin referrers. Has lower precedence than NoReferrers.
  NoReferrers	Removes all referrers.
  ReducedSystemInfo	Reduces the amount of system information obatainable through headers and javascript, also causes hardwareConcurrency to respond with two cores.
  RemoveClientHints	Removes client hints (information sent to servers about your system, similar to a user agent).
  SetIpv6ProbeFalse	Forces the result of the browser's IPv6 probing (i.e. IPv6 connectivity test) to be unsuccessful. This causes IPv4 addresses to be prioritized over IPv6 addresses. Without this flag, the probing result is set to be successful, which causes IPv6 to be used over IPv4 when possible.
  SpoofWebGLInfo	Return generic values for WebGLDebugRendererInfo to remove a potential data leak while preventing potential website breakage.
  IncreaseIncognitoStorageQuota	Makes Incognito and Guest profiles compute the storage quota with the same algorithm that regular profiles use. This makes it harder for websites to detect Incognito mode, but may allow sites to induce heavy memory pressure.

• Available only on desktop

  Feature	Description
  ClearDataOnExit	Clears all browsing data on exit.
  DisableLinkDrag	Prevents dragging of links and selected text. Allows selecting text from a middle of a link. Also allows starting selection without first clearing the existing one. This behaviour is similar to the one from older Opera. See ungoogled-software#2080 and ungoogled-software#2055 for more information.
  DisableQRGenerator	Disables the QR generator for sharing page links.

Flags for existing switches

Chromium contains switches that do no have corresponding entries in chrome://flags. For convenience, ungoogled-chromium has created entries for some of the commonly-used switches.

• Available on all platforms

  Switch	Description
  --disable-top-sites	Disables the top sites and most visited entries on the new tab page.
  --disable-webgl	Disable all versions of WebGL.
  --enable-low-end-device-mode	Force low-end device mode when set.
  --force-dark-mode	Forces dark mode in UI for platforms that support it.
  --no-default-browser-check	Disables the default browser check.
  --no-pings	Don't send hyperlink auditing pings.
  --webrtc-ip-handling-policy	Restrict which IP addresses and interfaces WebRTC uses.

• Available only on desktop

  Switch	Description
  --incognito	Start in Incognito.
  --start-maximized	Starts the browser maximized, regardless of any previous settings.