• January 25, 2023

Browser Fingerprinting Javascript

FingerprintJS – GitHub

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.
View Our Demo.
Quick start
Install from CDN

Run this code
Alternatively you can install from NPM to use with Webpack/Rollup/Browserify
npm i @fingerprintjs/fingerprintjs
# or
yarn add @fingerprintjs/fingerprintjs
import FingerprintJS from ‘@fingerprintjs/fingerprintjs’
// Initialize an agent at application startup.
const fpPromise = ();(async () => {
const fp = await fpPromise
const result = await ()
Full documentation
Upgrade to Pro version to get 99. 5% identification accuracy
FingerprintJS 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 99. 5% identification accuracy.
You can try Pro without usage limits for 10 days – no credit card required.
Full product comparison:
Open Source
Core Features
100% Open-sourceyesno1
Standard fingerprint signalsscreen, os, device name✓✓
Advanced fingerprint signalscanvas, audio, fonts✓✓
ID typefingerprintvisitorID2
ID lifetimeseveral weeksmonths/years
ID originclientserver
ID collisionscommonrare
Additional Features
Incognito mode detectionworks in all modern browsers – see our full list of browsers supported–✓
Server-side accuracy increasebased on additional server-side signals, such as TLS crypto support, ipv4/v6 data and others–✓
Query API & realtime Webhooksbuild flexible workflows–✓
Geolocationbased on IP address–✓
Data securityYour infrastructureEncrypted at rest
StorageYour infrastructureUnlimited up to 1 yr
RegionsYour infrastructureHosting in US and EU
ComplianceYour infrastructureGDPR, CCPA compliant3
SLANo SLA99. 9% Uptime
SupportGitHub communitySupport team via email, chat, and call-back within 1 business day
1. Pro uses the open source fingerprinting library as well as proprietary technology for increased accuracy and identifier stability.
2. VisitorIDs, 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. FingerprintJS Pro is GDPR and CCPA compliant as the data processor. You still need to be compliant as the data controller and use the identification for fraud under legitimate interest or ask for user consent.
Pro result example:
“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
//… }}
Live demo
⏱ How to upgrade from Open Source to Pro in 30 seconds
FingerprintJS Pro documentation
▶️ Video: use FingerprintJS 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.
Browser support
The library supports all popular browsers.
See more details and learn how to run the library in old browsers in the browser support guide.
See the contributing guidelines to learn how to start a playground, test and build.
Useful links
Easy to use bot detection in JS, new FingerprintJS project
The Top Browser Fingerprinting Techniques Explained

The Top Browser Fingerprinting Techniques Explained

To generate a highly accurate browser fingerprint, many techniques are used to gather information about the user that can differentiate them from millions of others online. In this article, we review some of the most common methods used in a browser fingerprinting script.
Also known as online fingerprinting, browser fingerprinting is a tracking and identification method websites use to associate individual browsing sessions with one site visitor. Using Javascript, a plethora of data can be collected about a user’s browser and device. When these pieces of information are stitched together, they reveal a unique combination of information that forms every user’s very own ‘digital fingerprint. ’ The browser fingerprint is traceable across browsing sessions, even when the user enters incognito browsing or uses a VPN to access a site.
Browser fingerprinting can be used to stop fraudsters from attempting to hack, spam, or spoof website owners by accurately identifying site users. Browser fingerprinting is more difficult to circumvent than cookies, as a user’s fingerprint does not change between incognito browsing sessions, or clearing browser data. To generate a browser fingerprint with enough accuracy (or entropy) to uniquely identify a web visitor, the script must use a variety of browser fingerprinting techniques to gather data (called signals) that would vary between visitors. While many visitors to a website may have the same model of iPhone, the software and drivers installed, geolocation, browser and OS version, and even minute variances in the hardware could be different. Each browser fingerprinting technique is able to gather one or more of these signals that aim to identify these small variances between users.
What Information is Gathered?
With browser fingerprinting, a lot of information can be gathered from the browser: the user’s device model, its operating system, its browser version, browser extensions, user timezone, preferred language settings, ad blocker used, screen size and resolution, and all the granular tech specs of his CPU, graphics card, and so on.
Browser fingerprinting technology can capture more than enough specifics about a user’s device and settings to pinpoint them in a sea of internet users. Read our beginner’s guide to learn more about how browser fingerprinting works and how each signal adds to a fingerprint’s overall accuracy and stability.
FingerprintJS’s browser fingerprinting technology employs several cutting-edge browser identification methods to gather over 100 individual signals. These signals are combined with server-side analysis and deduplication to generate a visitorID, providing a persistent and useful abstraction of a browser fingerprint, which can be volatile if a user changes settings or updates software on their device.
What Are Some of the Different Fingerprinting Techniques?
Canvas Fingerprinting
This browser fingerprinting technique takes advantage of the HTML5 canvas element to identify variances in a user’s GPU, graphics drivers, or graphics card. First, the browser fingerprinting script draws an image, often overlaid with text. Then, the script captures how the user’s browser has rendered the image and text. Every device with different hardware and drivers will render the image slightly differently, distorting its color and shape. A hash is then computed using the rendered image’s data, which serves as the ‘canvas fingerprint. ’
Like any other browser fingerprinting technique, the scripts used for canvas fingerprinting operate in the background to keep the user from realizing that the fingerprinting is occurring. This fingerprinting technique is both accurate and not too processing intensive, making it one of the most employed techniques in browser fingerprinting scripts.
To read more about this technique, read our in-depth article on Javascript canvas fingerprinting.
Canvas and WebGL rendered images, from AmIUnique. Due to how this visitor’s specific browser and device rendered these images, they can be narrowed down to a pool of fewer than 0. 01% of total visitors.
WebGL Fingerprinting
WebGL fingerprinting is very similar to Canvas fingerprinting as they both use the browser to render text and images off-screen. These images are then used to differentiate users based on their graphics drivers and device hardware.
Media Device Fingerprinting
This technique uncovers a list of all the connected media devices and their respective IDs on a user’s laptop or PC. This includes all internal media components like video cards, audio cards, and all connected or linked devices like headphones.
Media device fingerprinting is not widely used in fingerprinting functions as it requires the user to grant access to their microphone and camera to get a full list of connected devices. As such, this technique is useful for services that innately require webcam or microphone access, such as video chat services.
Audio Fingerprinting
While other fingerprinting techniques force browsers to render a text or image, this technique checks how their devices play sound. Minute differences in sound waves generated by a digital oscillator are impacted by the browser vendor and version used, as well as differences in CPU architecture.
To learn more about audio fingerprinting, read our in-depth tutorial on how audio fingerprinting works using the Web Audio API.
Putting it all together
Multiple fingerprinting techniques need to be used in conjunction with each other to generate a sufficiently accurate fingerprint for user identification. Each technique generates one or more signals, which are then collectively combined into a visitor hash that serves as an individual identifier.
Fingerprinting and Online Fraud Detection
When you’re dealing with fraud, take note that only a small number of your site visitors are responsible for fraudulent activities. Hence, your developer team has to find a way to isolate these site users, identify them, verify them through authentication, and add them to your site blacklist. However, you need to keep these security layers away from your trusted traffic since extra authentication steps can cause an unpleasant user experience. More strict site security can also slow down account accessibility, purchase making, and overall site engagement.
Browser fingerprinting techniques are incredibly useful to identify visitors with a pattern of fraudulent behavior, and then target only these visitors for additional security. Fraudsters often use identity concealing techniques like disabling cookies, surfing through a VPN, or using browsers in incognito mode. These are all areas where fingerprinting proves to be at its best since it identifies users quickly without the reliance on IP addresses and site cookies.
One of the most common fraud use cases is account takeover, where malicious users will try to hack a legitimate user’s account and make purchases or steal their identity. With browser fingerprinting and related user identification technologies, additional security can be added to the login process for suspicious traffic only. This makes it more difficult for untrusted traffic to log in and take over trusted users’ accounts.
If your website is experiencing brute force or bot attacks, a best practice is to ask users to solve a CAPTCHA after each unsuccessful login attempt. After three to five unsuccessful login attempts, set your system to lock out the user for a period of time.
If your users are often the target of phishing scams, you can require email or two-factor authentication when a new fingerprint attempts to log in. And if such fingerprints repeatedly visit your site, you can also blacklist them.
For virtually all types of fraud, the first step in stopping the malicious activity on your website is accurate user identification technology. That way, you can accurately single out the bad apples while keeping your trusted users satisfied with your website performance.
Whether you have a newly-built website or you’ve been in the online industry for years, you can safeguard your leads, clients, and business if you can stop fraud at the source. Start a 30-day trial to see what accurate user identification technology can do for you.
Browser Fingerprinting: What Is It and What Should You Do ...

Browser Fingerprinting: What Is It and What Should You Do …

Have you ever heard of browser fingerprinting? It’s okay if you haven’t, since almost nobody else has ever heard of it, either.
Browser fingerprinting is an incredibly accurate method of identifying unique browsers and tracking online activity.
Luckily, there are a few things you can do to wipe all of your fingerprints from the internet. But first, let’s start by exploring what, exactly, browser fingerprinting is.
Browser Fingerprinting: What Is It?
Browser fingerprinting is defined on Wikipedia as follows:
“A device fingerprint, machine fingerprint, or browser fingerprint is information collected about a remote computing device for the purpose of identification. Fingerprints can be used to fully or partially identify individual users or devices even when cookies are turned off. ”
That means that, when you connect to the internet on your laptop or smartphone, your device will hand over a bunch of specific data to the receiving server about the websites you visit.
Browser fingerprinting is a powerful method that websites use to collect information about your browser type and version, as well as your operating system, active plugins, timezone, language, screen resolution, and various other active settings.
These data points might seem generic at first and don’t necessarily look tailored to identify one specific person. However, there’s a significantly small chance for another user to have 100% matching browser information. Panopticlick found that only 1 in 286, 777 other browsers will share the same fingerprint as another user.
Websites use the information provided by browsers to identify unique users and track their online behavior. This process is therefore called “browser fingerprinting. ”
The uniqueness of browser information is closely related to the investigation method of the police and forensic teams, who identify suspects and criminals based on fingerprints at the crime scene.
The Integrated Automated Fingerprint Identification System (IAFIS) is a massive database that stores fingerprints of 70 million subjects of criminal cases, as well as 31 million prints from civil cases. That means that a large chunk of these fingerprints were collected for analysis purposes.
Browser fingerprinting works like that as well. Websites bulk-collect a large set of data of visitors in order to later use it to match against browser fingerprints of known users.
All of this information does not necessarily reveal exactly who you are, your name, and/or your home address, but it’s incredibly valuable for advertising purposes, as companies can use it to target certain groups. These groups have been formed by matching people based on browser fingerprinting.
Now, you might be wondering: why is this being done, and why is your data so incredibly valuable to these companies?
The international advertising industry and marketing machines love your data. They’ll do anything to get their hands on your data in order to track your online activities.
Tracking methods and data collection are extremely valuable because it allows advertising businesses to create a profile based on your data. The more data these businesses have, the more accurately they can target you with advertisements, which (indirectly) means higher revenue for the company.
Fortunately, it’s not all bad. Browser fingerprinting is also used to identify the characteristics of botnets because the connections of botnets are established by a different device every time.
Such analysis could lead to the identification of fraudsters and other suspicious activities that require investigation.
Also, banks use this method to identify potential fraud cases.
If an account is showing questionable online behavior, for example, a bank’s security system would be able to identify that the account is being accessed from multiple, different locations during a short period of time by analyzing unique fingerprinting.
By doing so, a hacker who logged into the account using a device that had never accessed the account before can potentially be identified.
All of these signs suggest potential fraud and usually trigger further investigation or the preventative freezing of an account.
Methods Used for (Fingerprint) Tracking
Websites use several different methods to track users on the internet. By doing so, they can collect information and fingerprint your browser – and you wouldn’t even know or see that websites are doing this!
Now, the question is: how do they do it?
The technology allows websites to interact with your browser and retrieve information. In the following sections, I’ll provide you with information about how websites interact with your browser and how they obtain information.
Cookies & Tracking
A common way for websites to obtain your data is by using cookies. Cookies are small packets of text files that are stored on your computer, which contain certain data that may give websites information to improve the user experience.
Websites remember and track individual computers and devices by loading the cookies (small data packets) onto your computer.
Every time you visit a website, your browser will download cookies. When you visit the same website at a later time, the website will assess the packets of data and provide you with a personally customized user experience.
Think about the font size or screen resolution you view on a website. If a website knows you’re always using an iPhone 8, it will provide you with the best settings for your iPhone. Also, this way, the website knows whether you’re a unique visitor or a returning visitor. Cookies also store data on browsing activity, habits, interests, and much more.
Furthermore, websites employ Javascript, which will interact with visitors in order to carry out certain tasks, such as playing a video. These interactions also trigger a response, and as such, they receive information about you.
Canvas Fingerprinting
The newest method to obtain browser information is called “Canvas Fingerprinting. ” Simply put, websites are written in HTML5 code, and inside that code, there is a little piece of code that takes your browser’s fingerprint.
So, how are websites doing that, exactly? Let me explain.
This new tracking method that websites employ to obtain your browser fingerprint is enabled by new coding features in HTML5.
HTML5 is the coding language used to build websites. It’s the core fundamentals of every website. Within the HTML5 coding language, there’s an element which is called “canvas. ”
Originally, the HTML element was used to draw graphics on a web page.
Wikipedia provides the following explanation on how exploiting the HTML5 canvas element generates browser fingerprinting:
“When a user visits a page, the fingerprinting script first draws text with the font and size of its choice and adds background colors. Next, the script calls Canvas API’s ToDataURL method to get the canvas pixel data in dataURL format, which is basically a Base64 encoded representation of the binary pixel data. Finally, the script takes the hash of the text-encoded pixel data, which serves as the fingerprint. ”
In plain English, what this means is that the HTML5 canvas element generates certain data, such as the font size and active background color settings of the visitor’s browser, on a website. This information serves as the unique fingerprint of every visitor.
In contrast to how cookies work, canvas fingerprinting doesn’t load anything onto your computer, so you won’t be able to delete any data, since it’s not stored on your computer or device, but elsewhere.
Browser Fingerprinting vs. Your IP Address
I believe that many online privacy-minded people, like myself, are aware of the fact that covering up your IP address is an important method to use to hide your online identity.
The IP address protocol is designed to send a request to a receiving web server every time a user interacts with a website or service because the receiving server needs an IP address to send a response to.
That means that your IP address is a unique string of numbers that points directly to your device. Tech-savvy website owners are even able to track what other websites you visit, the account you’re logged into, and sometimes even your geo-location.
Of course, this would require a bit more effort, but it’s kind of scary that it’s possible.
Test Your Browser’s Fingerprinting
There are various tools available that make it possible to test your browser identity. You can use “Am I Unique, ” “PANOPTICLICK” or “Unique Machine” to test the identity of your device.
Note: at the time of this writing, Unique Machine’s test tool is still being developed but should be released soon.
Any of these tools will review your browser’s fingerprint and assess how unique your data actually is.
Am I Unique uses a comprehensive list of 19 attributes (data points). The most significant attributes include whether cookies are enabled, what platform you’re using, what type of browser (as well as its version) and computer you’re using, and whether tracking cookies are blocked.
On Am I Unique’s website, simply click “View my browser fingerprint” to run the test.
When you click “View more details, ” you can see all of the specific information that your browser is providing to the server. My browser is unique among all the test samples they’ve gathered so far (almost 700, 000)!
You can also run a test with Panopticlick. It’s a research project of the Electronic Frontier Foundation (EFF).
On Panopticlick’s website, click “TEST ME” to run the test to see how safe your browser is against tracking.
Panopticlick also runs various tests to assess your browser identity. I’ve published my test results below.
Panopticlick tests whether your browser:
Blocks tracking ads
Blocks invisible trackers
Blocks “Whitelisted” trackers
Unblocks sites that promise to honor “Do Not Track”
Is, overall, protected against browser fingerprinting
As shown in the analysis, the results are mixed. I have “some protection” against web tracking, but it’s clearly not good enough. My browser is blocking certain items partially while not blocking other things at all.
This tracker concludes that my browser fingerprint is unique. Panopticlick recommends installing their Privacy Badger – more about that later in the “How to Defend Yourself Against Browser Fingerprinting” section.
How to Defend Yourself Against Browser Fingerprinting
It’s probably not possible to protect yourself completely against fingerprinting. Perhaps new software or other ways to sufficiently combat browser fingerprinting will be developed in the near future.
However, there are quite a few tools and methods available to enhance your online privacy and minimize the possibility of identification.
Find the most effective methods to protect yourself below.
Use Private Browsing Methods
Browsers like Chrome, Edge, Safari, and Firefox allow users to browse in incognito mode.
Incognito mode makes your browsing private by setting your “profile” to certain standard data points. These data points are part of your fingerprint, so, since many people use the same “profile” settings, the fingerprints look similar.
This will greatly reduce your chances of having a unique fingerprint.
Use Plugins
You can also opt to install plugins that disable trackers, which are employed by certain websites, from running on your browser.
Plugins like AdBlock Plus, Privacy Badger, Disconnect, and NoScript are designed to block scripts that potentially enable spying ads and invisible trackers from running in your browser.
For some websites, this means that the user experience might be somewhat less satisfactory. But it’s also possible to disable the plugins from running on websites that you trust by whitelisting them.
Panopticlick recommends using their Privacy Badger, which is a browser extension that blocks advertisers and other third-party tracking software from tracking your online activities.
NoScript requires more time to set up and use effectively because the plugin blocks JavaScript on every website by default. That means that you’ll have to enable JavaScript manually on every trusted website.
Disable JavaScript and Flash
One of the more effective methods you can use to protect yourself against browser fingerprinting is to disable JavaScript and Flash.
When JavaScript is disabled, websites won’t be able to detect the list of active plugins and fonts you use, and they also won’t be able to install certain cookies on your browser.
The disadvantage of disabling JavaScript is that websites won’t always function properly, because it’s also used to make websites run smoothly on your device. This will impact your browsing experience.
On the other hand, Flash can be disabled without a negative impact on the user experience. Generally, Flash only impacts the browsing experience when you visit very old websites.
Install Anti-Malware Software
Anti-malware software is always helpful, regardless of whether you’re looking for online privacy protection or you just desire overall protection for your device and personal files/data.
Malwarebytes and HitmanPro are both outstanding anti-malware software tools that run seamlessly alongside your antivirus software and serve as a second layer of protection.
In most instances, anti-malware blocks ads, harmful or annoying toolbars, and spyware software that might be running in the background on your system.
These software tools and scripts are directly linked to your browser’s fingerprint. So, it’s better to have a clean browser and delete these threats with an anti-malware tool.
When you install an anti-malware tool, be smart and go to the settings in order to enable automatic weekly or (at least) monthly full-system scans.
Use the Tor Browser
If you’re extremely serious about secure browsing and preventing browser fingerprinting, you should consider installing the Tor (The Onion Router) Browser.
The best way forward would be to run the Tor Browser in combination with a proper VPN. Due to the fact that Tor uses certain default settings, which are identical for every user, it’s harder to identify unique browser fingerprints.
Additionally, the Tor Browser aggressively blocks JavaScript code on websites.
The major downside of using the Tor Browser is the slow browsing speed, and the fact that it only protects the internet traffic sent through the Tor Browser and not others, like Firefox or Chrome.
Use a VPN
One of the most popular methods to hide an IP address is to install a Virtual Private Network (VPN).
As shown in the image below, a VPN is like a middle man. Instead of connecting directly to a web server, you connect to the VPN’s server first, and the VPN will connect you to a website. By doing so, your IP address will be unknown to the webserver.
Using a VPN is a very effective method to hide your IP address because the webserver can only see the IP of the VPN (which is probably used by many other users).
But, your IP address is only one aspect of your online identity.
Regardless of what IP the webserver can see, your browser settings, version, and so forth, which generate unique browser fingerprinting data, can’t be blocked out by a VPN.
That means that the data of your browser still allows the webserver to identify you as a unique visitor regardless of whether you’re using a VPN since your IP address is only one aspect of your browser fingerprinting profile.
A VPN is great at hiding your real IP address, but it’s not the most effective method to protect you against browser fingerprinting, as many other attributes are part of your fingerprint as well. Used in conjunction with other methods, though, a VPN can be a great asset.
Read my post about VPNs for more information.
My Final Thoughts
Browser fingerprinting is a serious threat to online privacy, and it goes a lot further than simply checking an IP address.
Browser fingerprinting uses an extensive list of data points that, altogether, create your browser fingerprint. Your browser fingerprint is likely to be extremely unique.
Websites can use your unique fingerprint to gather and generate an in-depth personal file of websites that you’ve visited or target you with very personalized ads.
There are various methods you can employ to cover up your prints on the internet. Let’s quickly review the most effective methods.
Use incognito mode
Implement security plugins
Install anti-malware tools
As shown in the “Test Your Browser’s Fingerprinting” section, my browser ended up having a unique fingerprint. However, after I put the methods listed above into practice, my browser became significantly more protected against fingerprinting.
As you can see below, I managed to reduce the level of uniqueness from 1 in 286, 777 to 1 in 93. 25, which is a huge difference.
Browser Fingerprinting FAQs
Are Plugins Available to Disable Trackers? Yes, plugins like AdBlock Plus, Privacy Badger, Disconnect, and NoScript are designed to block scripts that potentially enables spying ads and invisible trackers from running in your A Browser Fingerprinting Test Available? Various online tools are available to test your browser identity. You can use “Am I Unique, ” “PANOPTICLICK” or “Unique Machine” to test the identity of your Any Browser Automatically Block Browser Fingerprinting? Firefox and Tor both employ browser fingerprinting techniques. Both browsers require websites to ask for user permission before collecting data.
Contents [hide]Browser Fingerprinting: What Is It? Methods Used for (Fingerprint) TrackingTest Your Browser’s FingerprintingHow to Defend Yourself Against Browser FingerprintingMy Final ThoughtsBrowser Fingerprinting FAQsAre Plugins Available to Disable Trackers? Is A Browser Fingerprinting Test Available? Do Any Browser Automatically Block Browser Fingerprinting?

Frequently Asked Questions about browser fingerprinting javascript

What is browser fingerprinting Javascript?

Also known as online fingerprinting, browser fingerprinting is a tracking and identification method websites use to associate individual browsing sessions with one site visitor. Using Javascript, a plethora of data can be collected about a user’s browser and device.Apr 1, 2021

Is browser fingerprinting possible?

Your browser fingerprint is likely to be extremely unique. Websites can use your unique fingerprint to gather and generate an in-depth personal file of websites that you’ve visited or target you with very personalized ads. There are various methods you can employ to cover up your prints on the internet.Jul 27, 2021

How do I fingerprint my browser?

Browser fingerprinting happens when websites use special scripts to collect enough information about you — such as your browser, timezone, default language, and more — that they can uniquely identify you out of the sea of other internet users.Oct 22, 2020

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