FingerprintJS is a browser fingerprinting library that queries browser attributes and computes a hashed visitor identifier from them. Unlike cookies and local storage, a fingerprint stays the same in incognito/private mode and even when browser data is purged.

FingerprintJS is 100% open-source, but its accuracy is limited because it's only a client-side library without a backend.

Quick start

<script>
  // Initialize the agent at application startup.
  const fpPromise = import('https://openfpcdn.io/fingerprintjs/v3')
    .then(FingerprintJS => FingerprintJS.load())

  // Get the visitor identifier when you need it.
  fpPromise
    .then(fp => fp.get())
    .then(result => {
      // This is the visitor identifier:
      const visitorId = result.visitorId
      console.log(visitorId)
    })
</script>

Run this code

📕 Full documentation

⚛️ Sample usage with React on the StackBlitz platform

Use Fingerprint Pro to get 99.5% identification accuracy

Fingerprint Pro is a professional visitor identification service that processes all information server-side and transmits it securely to your servers using server-to-server APIs. Pro combines browser fingerprinting with vast amounts of auxiliary data (IP addresses, time of visit patterns, URL changes and more) to be able to reliably deduplicate different users that have identical devices, resulting in the 99.5% identification accuracy. Fingerprint Pro is available for Web, Android, iOS and other platforms.

Fingerprint Pro pricing starts at $200 per month for up to 100K API calls. Additional API calls are $2 per month for 1,000 API calls. A two-week free trial is available — no credit card is required. Sign up at https://dashboard.fingerprint.com/signup.

Pro plans start at $0/month - no credit card required.

Full product comparison:

1. Fingerprint Pro uses the open source fingerprinting library as well as proprietary technology for increased accuracy and identifier stability.

2. Visitor IDs, in comparison to fingerprints, include server-side techniques, are deduplicated, and utilize fuzzy matching to result in a more accurate and stable identifier. Fingerprint hashes rely on an exact match across all browser attributes, making them less stable across > 4-week time intervals.

3. Fingerprint Pro is GDPR and CCPA compliant, ISO 27001 certified, and SOC 2 Type II compliant. You still need to be compliant as the data controller and use the identification for fraud prevention under legitimate interest or ask for user consent.

{
  "requestId": "HFMlljrzKEiZmhUNDx7Z",
  "visitorId": "kHqPGWS1Mj18sZFsP8Wl",
  "visitorFound": true,
  "confidence": { "score": 0.995 },
  "incognito": false,
  "browserName": "Chrome",
  "browserVersion": "92.0.4515.107",
  "os": "Mac OS X",
  "osVersion": "10.15.6",
  "device": "Other",
  "ip": "192.65.67.131",
  "ipLocation": {
    "accuracyRadius": 100,
    "latitude": 37.409657,
    "longitude": -121.965467
    // ...
  },
  "firstSeenAt": {
    "global": "2022-03-16T11:26:45.362Z",
    "subscription": "2022-03-16T11:31:01.101Z"
  },
  "lastSeenAt": {
    "global": "2022-05-21T18:05:43.023Z",
    "subscription": "2022-05-20T05:41:29.926Z"
  }
}

Resources

🍿 Live demo

⏱ How to upgrade from open source FingerprintJS to Fingerprint Pro in 30 seconds

📕 Fingerprint Pro documentation

▶️ Video: use Fingerprint Pro to prevent multiple signups

Migrating from v2

• Migration guide
• V2 documentation

Version policy

See the compatibility policy for the API and visitor identifiers in the version policy guide.

Supported browsers

The library supports all popular browsers. See more details and learn how to run the library in old browsers in the browser support guide.

Where to get support

Using Issues and Discussions publicly will help the open-source community and other users with similar issues. However, if you require private support, please email us at [email protected].

Contributing

See the contribution guidelines to learn how to start a playground, test, and build.