@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:

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

Install from NPM

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