Audience
Web developers and security engineers requiring a solution for user identification without compromising privacy
About ThumbmarkJS
ThumbmarkJS is a fair, privacy-friendly fingerprinting library built by developers for developers. Offered under an MIT license, it can be installed via NPM or loaded from jsDelivr, and with just a few lines of JavaScript, importing the UMD bundle and calling tm.get(), it returns a consistent 32-character thumbmark fingerprint. For small projects requiring higher accuracy, a free API version is available, while the Pro version scales indefinitely and cost-efficiently for large-scale applications. Without complex setup or invasive tracking, ThumbmarkJS has been integrated into over 60,000 websites, handling more than 1 billion identifications and 200 thousand downloads per month. It is free, open source, and has been designed as an alternative to FingerprintJS. It generates distinct, persistent device fingerprints using web APIs like canvas, audio, fonts, WebGL, and more, enabling identification of browsers across sessions.