@fingerprint/agent

Makes a website visitor identifier from a browser fingerprint. Unlike cookies and local storage, fingerprint stays the same in incognito/private mode and even when browser data is purged. Provides additional information and higher accuracy compared to Open Source FingerprintJS.

Quick start

Get a pro key:

• Register a new PRO account at dashboard.fingerprint.com/signup (there is a free trial)
• After registration go to the dashboard and select the created subscription
• Go the "API Keys" page in the navigation side bar on the left side of the page
• Copy a key with type "Public"

Install from NPM

npm i @fingerprint/agent
# or
yarn add @fingerprint/agent

import Fingerprint from '@fingerprint/agent'

// Initialize an agent at application startup.
const fpPromise = Fingerprint.start({ apiKey: 'your-pro-key' })

;(async () => {
  // Get the visitor identifier when you need it.
  const fp = await fpPromise
  const result = await fp.get()

  // This is the visitor identifier:
  const visitorId = result.visitorId
  console.log(visitorId)
})()

Run this code

Alternatively you can install from CDN

<script>
  // Initialize the agent at application startup.
  const fpPromise = import('https://fpjscdn.net/v4/your-pro-key')
    .then(FingerprintJS => FingerprintJS.start())

  // 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>

Note that you need to replace your-pro-key with a public API key from the dashboard.

Run this code

See also

🍿 Live demo

⏱ How to upgrade from Open Source to Pro in 30 seconds

⬆️ How to migrate from Fingerprint version 3

📕 Fingerprint documentation

▶️ Video: use Fingerprint to prevent multiple signups