Fingerprint OSS is a fully open source browser fingerprinting service released under the LGPL-3.0 license. Unlike commercial "source available" options, it is truly free to use and backed by Cloudflare OSS.

npm install fingerprint-oss

Built with ethical guidelines at its core — supporting transparency, user privacy, and compliance with GDPR and other privacy regulations. Includes VPN, incognito, AdBlocker, and bot detection.

100% client-side operation (except GeoLocation API) with simple integration. Collects comprehensive system, browser, and environment data in one call.

import userInfo from 'fingerprint-oss';
const data = await userInfo();