detectIncognito.js


Efficiently detect Incognito mode & other private browsing modes across most modern browsers.

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Features

- ✅ Incognito detection on Google Chrome
- ✅ Private Window detection on Safari (macOS)
- ✅ Private Tab detection on Safari (iOS)
- ✅ Private Window detection in Firefox
- ✅ InPrivate Window detection on Microsoft Edge
- ✅ InPrivate Window detection on Microsoft Internet Explorer
- ✅ Private Window detection in Brave (see notes)
- ✅ Private Window detection in Opera

Demo

Check out the live demo.

Usage

Get the script from CDN (may be blocked by adblockers—see notes):

``html

`

Or install via NPM:

`bash
npm i detectincognitojs
`

`javascript
import { detectIncognito } from "detectincognitojs";

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

Supported Browsers

| Browser | Platform(s) | Versions | Notes |
|-----------------|-------------|---------------------|-----------------------------------------------------------------------------------------------|
| Safari | All | ≤ 18.4 | |
| Chromium | All | 50 to 137 Beta | Detection broken by predictable-reported-quota` flag (Issue #49) |
| Firefox | All | 44 to 138 | |
| MSIE | Windows | 11 | Requires Promise polyfill |

Notes

- False positives can occur in certain browser setups or Chrome Guest mode (Issue #21).
- Firefox Container Tabs aren't detected by this.
- The script must run over HTTPS—running locally or via HTTP might fail.
- Brave and uBlock Origin block the CDN; hosting the script yourself avoids this issue.
- An error is thrown if the browser can't be identified.

Similar Projects

- OverpoweredJS – An advanced browser fingerprinting & bot detection solution.

License

Copyright © 2025 Joe Rutkowski
Distributed under the MIT License.