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](https://dashboard.fingerprint.com/signup) (there is a free trial)
2. After registration go to the [dashboard](https://dashboard.fingerprint.com) 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
```bash
npm i @fingerprintjs/fingerprintjs-pro
# or
yarn add @fingerprintjs/fingerprintjs-pro
```
```js
import FingerprintJS from '@fingerprintjs/fingerprintjs-pro'
// Initialize an agent at application startup.
const fpPromise = FingerprintJS.load({ 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](https://stackblitz.com/edit/fpjs-pro-3-npm?file=index.js&devtoolsheight=100)
### Alternatively you can install from CDN
```html
```
Note that you need to replace `your-pro-key` with a public API key from the [dashboard](https://dashboard.fingerprint.com).
[Run this code](https://stackblitz.com/edit/fpjs-pro-3-cdn?file=index.html&devtoolsheight=100)
## See also
🍿 [Live demo](https://fingerprint.com/demo)
⏱ [How to upgrade from Open Source to Pro in 30 seconds](https://dev.fingerprint.com/v3/docs/migrating-from-fingerprintjs-to-fingerprint-pro#migrating-from-fingerprintjs-v3-open-source-to-pro)
⬆️ [How to migrate from Fingerprint Pro version 2](https://dev.fingerprint.com/v3/docs/migrating-from-pro-v2)
📕 [Fingerprint Pro documentation](https://dev.fingerprint.com)
▶️ [Video: use Fingerprint Pro to prevent multiple signups](https://www.youtube.com/watch?v=jWX9P5_jZn8)
