# fingerprintjs/fingerprintjs

The most advanced free and open-source browser fingerprinting library

Repository: https://github.com/fingerprintjs/fingerprintjs
Canonical: https://ross.abutalabs.com/products/fingerprintjs
Homepage: https://fingerprint.com/github/
Language: TypeScript
License: MIT
License Family: permissive
Topics: javascript, detection, identification, fingerprint, fraud-detection, fraud, audio-fingerprinting, browser, fingerprinting, browser-fingerprint, visitor-identifier, fingerprintjs, browser-fingerprinting
Last push: 2026-08-09T21:31:31+00:00

## Health v2 (maintenance only)
Score: 86/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 96, release rhythm 66, longevity 100
- inputs: {"age_days": 4221, "days_push": 24, "days_rel": 148, "gap_med": 40.0, "n_releases_24m": 9}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 28354, forks 2611 (observed 2026-08-28T04:11:48.289648+00:00)

## What it is
FingerprintJS is an open-source, client-side browser fingerprinting library that queries browser attributes and computes a hashed visitor identifier. Unlike cookies or local storage, the identifier remains stable in incognito mode and after browser data is purged.

## Use cases
- identify returning visitors without cookies
- detect users in incognito or private browsing mode
- prevent duplicate signups and trial abuse
- flag suspicious or fraudulent traffic client-side
- generate a stable device identifier for analytics
- detect banned users returning to a site

## When to choose
- you need a free, MIT-licensed, client-side visitor identifier
- you want fingerprinting that works in incognito mode without a paid service
- you need a lightweight npm or CDN library for browser identification

## When to avoid
- you need server-side signals like VPN, bot, or emulator detection (use Fingerprint Pro)
- you require the highest long-term identifier accuracy with fuzzy matching
- you need mobile native identification in iOS or Android apps
- your use case forbids fingerprinting, e.g. Google Analytics integration

## Facets
- artifact type: library
- maturity: active
- function: security, sdk, developer-tools
- domain: security, web-development, privacy, frontend
- platform: browser, cross-platform
- tags: browser-fingerprinting, visitor-identification, fraud-detection, incognito-detection, client-side, typescript, nodejs

## Member repositories
- fingerprintjs/fingerprintjs (main) score 86

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:48.289648+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:54:24.096848+00:00, confidence not recorded.
  - readme: https://github.com/fingerprintjs/fingerprintjs (fetched 2026-08-28T04:11:48.289648+00:00, sha 878ec99ed996)
  - homepage: https://fingerprint.com/github/ (fetched 2026-08-29T07:51:23.534748+00:00, sha 9cfed3e866ea)
  - site_page: https://docs.fingerprint.com (fetched 2026-08-29T07:51:23.544385+00:00, sha d3ff8680d17d)
  - site_page: https://docs.fingerprint.com/docs/fingerprintjs-pro-google-tag-manager (fetched 2026-08-29T07:51:23.551031+00:00, sha 1e1d8848d195)
  - site_page: https://docs.fingerprint.com/docs/react (fetched 2026-08-29T07:51:23.553092+00:00, sha 01c738dd6711)
  - site_page: https://docs.fingerprint.com/docs/fingerprintjs-pro-and-chrome-extension (fetched 2026-08-29T07:51:23.554789+00:00, sha 7b71123933c7)
  - site_page: https://docs.fingerprint.com/docs/angular (fetched 2026-08-29T07:51:23.556617+00:00, sha ba77c9cc98d9)
  - site_page: https://docs.fingerprint.com/docs/flutter (fetched 2026-08-29T07:51:23.558332+00:00, sha b8e7537ec815)
  - site_page: https://fingerprint.com/pricing (fetched 2026-08-29T07:51:23.546902+00:00, sha 35aa3e076ec9)
  - site_page: https://fingerprint.com/integrations (fetched 2026-08-29T07:51:23.549182+00:00, sha b28d069342be)
- Data as of 2026-08-30T08:39:29.467469+00:00.