Introducing the User Identification Library - FingerprintJS

Problem

We always want to know how many people are using our website, track visits, or identify unique users.

One simple way to do that is to require users to log in, which allows us to easily capture sessions through the user ID stored in the system. This method works well, but it's not always possible to get users to log in. Therefore, we need to find an alternative solution to identify users.

What is FingerprintJS

FingerprintJS is a library that provides the most accurate device identification for mobile and web devices. FingerprintJS supports cross-platform identification from Android, iOS to web browsers.

We know that the browser acts as a bridge for users to access websites. The browser itself contains a lot of information about itself as well as user information, such as browser type, version, display size, operating system, IP address, and much more. Visit https://coveryourtracks.eff.org to learn more about the information that browsers can "fetch" from you. This information, if successfully exploited and processed, can provide a unique identification for the user currently using it.

We may have encountered the need to identify users without using the login feature. Therefore, we need a way to mark whether a user has used the application before or not. A simple method is to generate a random identification string and store it in the cache. This method is quick and easy, but if the cache is cleared, everything will start from scratch. Therefore, we need a better user identification solution.

You can create your own algorithm to generate identification based on the data collected from the browser, or you can use the FingerprintJS library to do so. FingerprintJS has two versions: Open Source and Pro. According to their claims, the Open Source version has an accuracy of up to 60%, while the Pro version has an accuracy of up to 99.5%. However, when using the Pro version, you need to make requests to FingerprintJS's server to perform the identification process and there is a limit of 20,000 requests per month. If you exceed this limit, you will need to pay extra to use the service.

FingerprintJS will calculate based on the collected data to generate a user identification string like this:

x6e9RzbUC2P96yckcMih

How to Use

FingerprintJS provides various ways to use it.

Using a CDN:

  const fpPromise = import('https://openfpcdn.io/fingerprintjs/v3')
    .then(FingerprintJS => FingerprintJS.load())

  fpPromise
    .then(fp => fp.get())
    .then(result => console.log(result.visitorId))

Or through npm:

npm i @fingerprintjs/fingerprintjs

import FingerprintJS from '@fingerprintjs/fingerprintjs'

const fpPromise = FingerprintJS.load();

(async () => {
  const fp = await fpPromise
  const result = await fp.get()
  console.log(result.visitorId)
})()

To use the Pro version, you need to sign up for an account on FingerprintJS, and the system will display the tracking code to be added to your website.

Summary

FingerprintJS is a solution for quickly and accurately identifying users without requiring them to log in. My blog also uses FingerprintJS to provide the best experience for readers. If your next project requires user tracking without login, then you know what to do, right.