alwazw / detectincognito

JavaScript detection of Incognito & other private browsing modes on Chrome, Edge, Safari, Brave, Firefox, Opera and MSIE.

Note: The npm package is now detectincognitojs.

detectIncognito.js

detectIncognito.js can be used to detect incognito mode & other private browsing modes on most modern browsers as of 2024.

• Detects Incognito mode on Google Chrome
• Detects Private Windows on Safari for macOS
• Detects Private Tabs on Safari for iOS
• Detects Private Windows in Firefox
• Detects InPrivate Windows on Microsoft Edge
• Detects InPrivate Windows on Microsoft Internet Explorer
• Detects Private Windows in Brave (see notes)
• Detects Private Windows in Opera

Demo

https://detectincognito.com/

Usage

Get script from CDN (may be blocked by adblockers, see notes)

<script src="https://cdn.jsdelivr.net/gh/Joe12387/detectIncognito@main/dist/es5/detectIncognito.min.js"></script>

Or install from NPM

npm i detectincognitojs

import { detectIncognito } from "detectincognitojs";

Run the detect function

detectIncognito().then((result) => {
  console.log(result.browserName, result.isPrivate);
});

Supported Browsers

Browser	Platform(s)	Versions	Notes
Safari	iOS	8 to 18 Beta 3
Safari	macOS	≤ 17.5
Chrome/Chromium	All	50 to 127 Beta
Edge	All	15 to 18; 79 to 126
Firefox	All	44 to 128
Brave	All	≤ 1.67	CDN is blocked if shields are up
MSIE	Windows	11	Promise polyfill required

Please note that although this script works on almost all modern browsers, detecting private modes in browsers is very much an arms race. As such, I cannot guarantee that this script will continue to work into the future. However, I will continue to actively maintain this script to support as many browsers as is possible.

If you are aware of any modern browsers this script does not work with, please let me know by creating an issue.

Notes

• There will be a false positive in certain browser configurations, as well as in Chrome's Guest mode. (Issue #21).
• This script does not detect Container Tabs on Firefox as they work differently compared to private mode.
• An error will be thrown if the browser cannot be identified.
• The script only works remotely on a web server using HTTPS. Running the script locally or with HTTP may produce a false result, or it may not run at all.
• Brave and uBlock Origin currently block the script from loading from the CDN. Hosting the script elsewhere should bypass this.

Similar Projects

• Overpowered Browser Fingerprinting Script
• Browser Fingerprinting Resistance Research

License

Copyright (c) 2024 Joe Rutkowski

Released under MIT License