Your web browser reveals more information than you think.
Notably, with each web access the browser reveals the Operating System
(e.g. Windows 8.1, Mac OS X 10.9, or Ubuntu 14.04)
and the CPU. Check the Masking Agent demo for your current configuration.
Mostly, the information about your platform is not needed to browse the web, at all.
If you're using an older, more vulnerable computer, you may not want to be so generous with this information.
In general, it's a good idea to control the information that you transmit.
There are several Firefox add-ons available that let you mimic a completely different browser,
i.e. browser application and platform. But none of them meet my requirements:
- Maintain the Firefox browser name and version.
- Allow users to control how the platform information is replaced.
So, I made Masking Agent.
The information shown below is available to every web site you visit.
If you don't have Masking Agent installed and enabled, your platform details are plainly visible.
Revisit this page with Masking Agent installed to see the differences.
Frequently Asked Questions
Does the User-Agent automatically increment Firefox application versions?
Yes. Only the platform information is masked, nothing else. The Firefox version
is reflected in the User-Agent, even after updates. For example:
Mozilla/5.0 (masking-agent; rv:36.0) Gecko/20100101 Firefox/36.0
What is used to replace the platform information?
The default replacement text is 'masking-agent'. But there are two other options.
The second option is a randomized, scrambled text.
The randomize option is introduced in Masking Agent version 1.4.0.
The third option is your own custom text.
How do I configure Masking Agent?
In Firefox, go to your installed add-ons and find Masking Agent.
Click the "Preferences" button of this add-on. At the bottom there are two settings.
Use the first one to choose between the default text, the randomized text, and the custom text.
The second setting is used only if you selected the custom text option, for your custom replacement text.
Why use a randomized text?
That makes it ever harder to track you, because your browser finger print changes every time you start Firefox.
Does the randomized text change during my bank sessions?
Can I change the Masking Agent settings during my bank sessions?
No. Do not tinker with Masking Agent during important browser sessions.
When does the randomized text change?
It changes (1) when you start the Firefox application,
(2) when you enable the Masking Agent add-on, in the Add-ons Manager,
(3) when you activate Masking Agent, using the toolbar button,
(4) when you change the settings of Masking Agent, in the Add-ons Manager.
Can I temporarily deactivate Masking Agent?
Yes. Look for the Masking Agent toolbar button, with the same icon as shown above.
The toolbar button is introduced in Masking Agent version 1.4.0.
The toolbar button temporarily deactivates Masking Agent. When deactivated, the button turns gray
and your platform information is visible again for web sites.
Press it again to re-activate Masking Agent.
While deactivated, you can still change the settings of the add-on.
Masking Agent is also deactivated when you disable the add-on from the Add-ons Manager.
But that disables the settings as well.
Does everything still work after I install it?
Yes. Your platform information is not needed to browse web sites, view flash animations,
What are the risks?
Sometimes your platform information is needed to decide what software to offer for downloading,
or which plug-in to run.
You can just temporarily deactivate the add-on using the toolbar button and reload the web page.
Alternatively, you can disable the add-on entirely, without restarting Firefox, and reload.
But the toolbar button is a lot easier to use.
Can I add a white list to exclude one or more sites?
No. Simply deactivate it when necessary, using the toolbar button.
Is my privacy protected with this add-on?
No. But it has improved.
A web site displays the mobile version of its web pages.
That's because some web sites fall back to the mobile lay-out, if they get confused about the client platform.
You can just temporarily deactivate Masking Agent using the toolbar button, or
disable the add-on (restartless), and reload the web page.
NB: Site specific User-Agents are no longer supported in Firefox 25 and up.
(In older versions) The Firefox version is not incremented in the User-Agent after a Firefox update.
Please follow the Reset instructions below.
(In older versions) The User-Agent set by Masking Agent persists after disabling or uninstalling the add-on.
Please follow the Reset instructions below.
Resetting Masking Agent
When the add-on is not working as described:
- In Firefox, go to your installed add-ons in the Add-ons Manager and find Masking Agent.
- Click the "Disable" button of this add-on.
- Open a new tab or window, and navigate to address
- From the displayed list of preferences, reset the following preferences, i.e.
right-click each preference separately, and select "Reset" from the context menu:
- Return to your installed add-ons and re-enable Masking Agent.