Extracted from User-Agent using UAParser.js.
The OS version is parsed from your browser's User-Agent string and provides more specific information about your operating system. This attribute:
Operating system version information became crucial as different OS versions introduced new features, APIs, and security updates. Websites need version details to:
Different versions of the same OS can have vastly different capabilities:
Format: Windows NT kernel version (e.g., "10.0", "6.3")
Example: "Windows NT 10.0" = Windows 10 or 11
Format: Major.Minor.Patch (e.g., "14.1.0")
Example: "14.1" = macOS Sonoma 14.1
Format: Major_Minor_Patch (e.g., "17_1_1")
Example: "17.1.1" = iOS 17.1.1
Format: Version number (e.g., "14", "13")
Example: "14" = Android 14
| Windows Version | NT Version | Release Year |
|---|---|---|
| Windows 11 | 10.0 | 2021 |
| Windows 10 | 10.0 | 2015 |
| Windows 8.1 | 6.3 | 2013 |
| Windows 8 | 6.2 | 2012 |
| Windows 7 | 6.1 | 2009 |
| macOS Name | Version | Release Year |
|---|---|---|
| Sonoma | 14.x | 2023 |
| Ventura | 13.x | 2022 |
| Monterey | 12.x | 2021 |
| Big Sur | 11.x | 2020 |
| Catalina | 10.15 | 2019 |
Current: iOS 17.x (2023)
Recent: iOS 16.x (2022), iOS 15.x (2021)
Note: iOS users typically update quickly due to easy OTA updates
Current: Android 14 (2023)
Recent: Android 13 (2022), Android 12 (2021)
Note: Android version fragmentation is common; many users on older versions
| Operating System | Accuracy | Notes |
|---|---|---|
| Windows | High | NT version clearly indicates Windows version |
| macOS | Very High | Precise version number (e.g., 14.1.2) |
| iOS | Very High | Exact version including patch level |
| Android | Variable | Depends on manufacturer; sometimes generic |
| Linux | Low | Often just reports "Linux" without distro version |
| Chrome OS | High | Reports Chrome OS version number |
These browsers intentionally report generic OS versions (e.g., "Windows 10" regardless of actual version) to reduce fingerprinting.
OS version significantly increases fingerprinting uniqueness. Combined with OS name, browser version, and other attributes, it can uniquely identify your device.
Running the latest version suggests tech-savvy user; outdated versions may indicate casual users or enterprise environments with slow update cycles.
Very old OS versions suggest older hardware (e.g., iPhone 6 can't run iOS 17).
Enterprise environments often lag behind consumer OS versions by months or years.
Unsupported versions indicate potential security vulnerabilities and easier exploitation.
OS version is a powerful fingerprinting component because:
Attackers can identify vulnerable OS versions and serve targeted exploits. For example, users on Windows 7 (unsupported since 2020) are prime targets for malware.
If you're one of few users on a specific version (e.g., macOS 12.3.1), you can be tracked across websites even without cookies, just by your unique version signature.
Banks and services may flag unusual OS versions (very old or very new) as potentially fraudulent.
Controlling OS version disclosure is challenging since it's embedded in the User-Agent string:
Browser Extensions:
Limitations:
Strategy: All users report the same generic version
Example: Everyone shows "Windows NT 10.0" or "macOS 10.15" regardless of actual version
Result: Maximum anonymity through uniformity
Enable: about:config → privacy.resistFingerprinting = true
Effect: Reports generic Windows 10 or macOS version
Trade-off: Some sites may not optimize correctly
Strategy: Standardizes User-Agent in Shields mode
Effect: Reports common versions to blend in
Counterintuitive Privacy Tip:
Keeping your OS updated to the latest version actually improves privacy in some ways:
For balanced privacy and functionality:
For maximum privacy: