Section: User Commands (1)
Updated: July 2020
Page Index


icecat - IceCat - GNU version of IceCat browser  


icecat [ ,options /... ] [,URL/]  


Gnuzilla IceCat is an open-source web browser, designed for standards compliance, performance and portability.

GNUzilla is the GNU version of the GNU suite, and GNU IceCat is the GNU version of the IceCat browser. Its main advantage is an ethical one: it is entirely free software. While the IceCat source code from the GNU project is free software, they distribute and recommend non-free software as plug-ins and addons.

In addition, GNU IceCat includes some privacy protection features, included in a separate addon:

Some sites refer to zero-size images on other hosts to keep track of cookies. When IceCat detects this mechanism it blocks cookies from the site hosting the zero-length image file. (It is possible to re-enable such a site by removing it from the blocked hosts list.) Other sites rewrite the host name in links redirecting the user to another site, mainly to "spy" on clicks. When this behavior is detected, IceCat shows a message alerting the user.

Origin of the name

The name IceCat was coined to show our relationship to the GNU IceCat browser. Ice isn't Fire and a Cat isn't a Fox, so it is clearly a different package (we don't want GNU blamed for our mistakes, nor cause confusion with their trademarks), but is equally clearly intimately related (of course nearly all of the work comes from the GNU foundation effort, so we want to give credit).



A summary of the options supported by icecat is included below.

X11 options

X display to use
Make X calls synchronous
--g-fatal-warnings Make all warnings fatal

IceCat options
-h or --help
Print this message.
-v or --version
Print IceCat version.
-P <profile>
Start with <profile>.
--profile <path>
Start with profile at <path>.
Start with migration wizard.
Start with ProfileManager.
Do not accept or send remote commands; implies --new-instance.
Open new instance, not a new window in running instance.
--UILocale <locale> Start with <locale> resources as UI Locale.
Disables extensions and themes for this session.
Allows downgrading a profile.
--MOZ_LOG=<modules> Treated as MOZ_LOG=<modules> environment variable,
overrides it.
--MOZ_LOG_FILE=<file> Treated as MOZ_LOG_FILE=<file> environment variable,
overrides it. If MOZ_LOG_FILE is not specified as an argument or as an environment variable, logging will be written to stdout.
Run without a GUI.
Save recordings for all content processes to a directory.
Open a browser window.
--new-window <url> Open <url> in a new window.
--new-tab <url>
Open <url> in a new tab.
--private-window <url> Open <url> in a new private window.
Open Preferences dialog.
--screenshot [<path>] Save screenshot to <path> or in working directory.
--window-size width[,height] Width and optionally height of screenshot.
--search <term>
Search <term> with your default search engine.
--setDefaultBrowser Set this app as the default browser.
Open the Browser Console.
Open the Browser Toolbox.
--wait-for-jsdebugger Spin event loop until JS debugger connects.
Enables debugging (some) application startup code paths. Only has an effect when `--jsdebugger` is also supplied.
Open DevTools on initial load.
--start-debugger-server [ws:][ <port> | <path> ] Start the debugger server on
a TCP port or Unix domain socket path. Defaults to TCP port 6000. Use WebSocket protocol if ws: prefix is specified.
--recording <file> Record drawing for a given URL.
--recording-output <file> Specify destination file for a drawing recording.



/usr/bin/icecat - shell script wrapping icecat
/usr/lib64/icecat/icecat-bin - icecat






To report a bug, please mail to



For a full list of the people who are credited with making a contribution to Mozilla. See
The Free Software Foundation (FSF) is a nonprofit with a worldwide mission to promote computer user freedom. We defend the rights of all software users. See