Typesetting letters

Fluxfonts – font fingerprint cloaking

Fluxfonts is a specialized tool that attempts to tackle the privacy concerns raised by the possibility to collect information about the fonts installed on a system. Such information can be used to uniquely identify a system. With Fluxfonts, new fonts are randomly created and removed to prevent the same fingerprint from being recreated.

Font fingerprinting is a technique which is difficult and usually inconvenient for users to circumvent by other means. Fluxfonts is fully automated and runs in the background. By effectively always having a new unique fingerprint, it should prevent a system from being (re‐)identified between applications and web sites/‐browsers.


Fluxfonts version 2.0 (2017‐03‐04)

Get the latest release of fluxfonts on GitHub.

Fluxfonts runs on macOS, Linux, FreeBSD, and Windows 10.

Get notified of new releases by subscribing to the fluxfonts “appcast” feed.

About fingerprinting

Device fingerprinting is a technique where various small bits of information is collected from a computer and combined into a uniquely identifying set of information. With enough information, this fingerprint can be considered globally unique. A study by the Electronic Frontier Foundation (EFF) concludes that it should be possible to create a globally unique fingerprint from the information exposed by a web browser.

With a globally unique fingerprint, the same computer—and thus it’s user—can be reidentified across different contexts that would otherwise not be able to share information between them. Contexts such as different web advertisement networks, social networking sites, and a locally running program’s online systems. Being able to globally identify—and even reidentify at a later time—a user raises serious privacy concerns.

Computers especially are with time configured with subtle differences that make them unique. In the context of web browsers, this information can include: User‐Agent string (the browser make and version), the plug‐ins and fonts installed on the system, browser settings such as privacy and language options (as exposed in requests), IP address, and more.

The EFF has an online tool that exposes some of the information that can be collected by a web site through the standard features of a web browser. Another alternative is BrowserLeaks’ fonts tester. These tools can be used to observe the effect of the Fluxfonts program.

Copyright © 2012–2016 . The Fluxfonts program is licensed under a BSD 2-Clause License.


  1. I’m definitely going to try this out, but I’m concerned that this will just end up creating a ton of fonts, resulting in significant start-up delay and clutter of font selection menus. Is this correct?

    1. Hi, thank you for your interest in Fluxfonts!

      No, it wouldn’t flood your system with random fonts. You’ll have one–six randomly named fonts that rotate every so often (random rotation cycle depending on battery status). Fluxfonts doesn’t remove the fonts if you stop the service, so if you uninstall you’ll have to clean up one–six fonts manually. If you continue using the program, however, it will never add more than six fonts to your system. Read through main.c (fairly readable) if you want to understand the logic better.

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