ungoogled-chromium/docs/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 https://github.com/ungoogled-software/ungoogled-chromium/issues/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 https://github.com/ungoogled-software/ungoogled-chromium/issues/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 https://github.com/ungoogled-software/ungoogled-chromium/issues/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.

• ### 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 https://github.com/ungoogled-software/ungoogled-chromium/pull/2080 and https://github.com/ungoogled-software/ungoogled-chromium/discussions/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.