Updated 1 month ago by Yelena

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JS.Navigator is a set of JavaScript objects that stores various parameters and their values describing specifics of a computer it executes on. All JS.Navigator object parameters are accessible by a browser. Since they possess a certain uniqueness, especially when combined, websites may utilize them for user fingerprinting and tracking. 

This article describes different browser fingerprinting parameters that can be set in the "Edit profile" → "Advanced" → "Navigator" section.


A user agent is a short string native to the browser. By reading this string a website can identify your browser and operating system versions. When creating a browser profile, a user agent value is retrieved from the fingerprint database. This is an example of a user agent:

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

In this case, the website will assume that you are using Windows 10 and Chrome 90. The "NT x" value is the Windows release version.

If you set the User-Agent value manually, make sure to specify a corresponding Platform value. Discrepancies in User-Agent and Platform values are a big red flag. 

Screen resolution

Analyzing the screen resolution value is a commonly used browser fingerprinting method. Websites may also analyze discrepancies between the screen resolution declared by a browser and the available screen area size.

In Multilogin a screen resolution is retrieved from the fingerprint database upon browser profile creation. You may also change this parameter by either selecting one from the list or entering a custom one. The screen resolution list and resolutions you receive automatically are both adjusted to the Operating System chosen on the Overview page.

You can also customize this setting for all new profiles in "My account" → "Preferences". Learn more about it here.

Multilogin will launch a browser maximized to the resolution set in browser profile settings. Having a browser window maximized is a typical behavior for most users, and we do not advise minimizing it. We also do not recommend using screen resolutions that are bigger than your native one. 

If you work in a team and plan to share profiles, we recommend that their screen resolution doesn't exceed that of the smallest screen used in your team. For example, if your device is 4K (3840 x 2160 pixel) and your colleague uses a Full HD (1920 x 1080 pixel) display, the resolution in a browser profile should be 1920 x 1080 or smaller.


The Language property helps websites to identify your preferred language. Based on this value websites may adjust their content language, if it's available. As with any other Navigator object value, it may be used to fingerprint your browser.

When creating a browser profile, the most popular language property is set. Multilogin does not retrieve this value from a fingerprint database since this could lead to a major mismatch between a browser language and your IP location. For example, you could end up having the Filipino language preference somewhere in Germany. 

Instead, we provide a convenient tool to edit this value. You may both copy-paste the Language parameter from your regular browser (e.g. Chrome) or set it using our builder. 

If you would like your web pages to be in a specific language, you can select it here: click "Edit" → search your language → drag and drop it at the top of the list on the right. If a web page is available in the selected language, it will be used to display it.

Browser interface language is the same as your OS language. If you would like to change it, the system language on your computer must be changed first.


The platform is a Navigator object parameter indicating the platform a browser is compiled for.

When creating a browser profile, a Platform value is retrieved together with a user agent. Both values are affected by the Operating System filter from the Overview page. You can change it on the Navigator page.

If you set the Platform value manually, make sure to set a corresponding User-Agent value. Discrepancies in User-Agent and Platform values are a big red flag. 

Possible Platform values

For desktop browsers

For mobile browsers

  • Linux i686
  • Linux armv7l
  • MacIntel
  • Win64
  • Win32
  • iPhone
  • iPod
  • iPad
  • Android


DoNotTrack (DNT) is a Navigator object property that returns the user's do-not-track browser setting. Originally it was meant to provide a user with the possibility to opt out of being tracked. However, most websites do not honor this choice. Instead, they use it as an additional data point to increase the precision of user fingerprinting. 

In Multilogin, the default value for DoNotTrack is "Off". This matches the behavior for an absolute majority of users. While it is possible to change this setting manually, we advise to leave the default value in all browser profiles.


BuildID is a Navigator property, which returns the build identifier of the browser. This value is specific to only Firefox-based browsers. Typically, BuildID comes in YYYYMMDDHH format.

Multilogin retrieves the BuildID value from a fingerprint database for Stealthfox browser profiles. It is not advised to change this parameter manually.


HardwareConcurrency is a Navigator object parameter which indicates the number of CPU processors available to run threads on a user's computer. In Multilogin, the range is restricted to the most common values: 2, 4, 8, 12 and 16. If a different value is retrieved from the fingerprint database, it will be replaced by one of the commonly used ones.


The Oscpu property is a Navigator object parameter which refers to the version of a user's operating system. This value is present only in Firefox-based browsers (Stealthfox in Multilogin).

If you set the Oscpu parameter manually, make sure to set a corresponding User-Agent value. Discrepancies in User-Agent and Oscpu values are a big red flag.

Possible Oscpu values




  • Intel Mac OS X 10.14
  • Intel Mac OS X 10.12
  • Intel Mac OS X 10.11
  • Windows NT 10.0; Win64; x64
  • Windows NT 6.3; WOW64
  • Windows NT 6.3; Win64; x64
  • Windows NT 6.1
  • Windows NT 6.1; Win64; x64
  • Linux x86_64
  • Linux i686

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