Font Fingerprint Test
Discover which fonts are installed. Font enumeration reveals OS, software, and preferences—creating a unique fingerprint.
Why Fonts Matter
Installed fonts reveal your OS, professional software (Adobe), developer tools, and language preferences (5-8 bits of entropy for fingerprinting).
Uniqueness Score
Operating System Detection
Detected Fonts by Category
System Styles
How Font Fingerprinting Works
Uses canvas text measurement: measures baseline text width with generic fonts, then with specific font + fallback. If widths differ, font is installed.
5-8 bits of entropy: OS detection (Arial=Windows, Helvetica=Mac), Adobe fonts indicate creative professionals, developer fonts indicate programmers, Asian fonts reveal language preferences.
How it works: Each operating system ships with unique default fonts. Windows includes Segoe UI and Calibri, macOS has Helvetica Neue and SF Pro, Linux typically has Liberation and DejaVu fonts. By detecting which OS-specific fonts are present, we can infer the actual operating system—even if the User Agent string claims otherwise. This technique can expose fingerprint spoofing attempts.
Difficult to prevent: browser extensions can randomize but may break layouts. Privacy browsers (Tor, Brave) limit font access. Best: minimize installed fonts and ensure OS fingerprint matches User Agent to avoid detection.