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What is Browser Fingerprinting? How it Works And How To Stop It

Browser fingerprinting identifies you and collects data about your online travels. In this article, we'll discuss what browser fingerprinting is, how it works, and how you can protect against it.

At a Glance

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.

What Is Browser Fingerprinting?

Wikipedia defines browser fingerprinting 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, time zone, 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 one in 286,777 other browsers will share the same fingerprint as another user.

Websites use the information that browsers provide to identify unique users and track their online behavior. This process is therefore called “browser fingerprinting.”

Browser Fingerprinting

Browser Fingerprinting Examples

Websites mostly use browser fingerprinting to track your online travels. The large majority of sites use this data to personalize the advertisements and information that they serve up to you.

When you use a search engine, you leave behind quite a bit of sensitive data, which data brokers glean to sell to interested third parties, like health and life insurance companies. When a data broker sells your data to an insurance company, the insurer may decide that you’re a health risk due to the information you looked up, charging you higher rates.

Online merchants will set your pricing due to your location. If browser fingerprinting shows that you live in an affluent area, you may see your in-browser pricing increase. Heck, I learned the other day that Target “targets” its customers with different pricing related to their location. If you check pricing from across town from your local Target, the price will likely be cheaper than if you check it while you’re in their parking lot.

How Browser Fingerprinting Works

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 and criminal histories of 70 million subjects of criminal cases, as well as 31 million prints from civil cases and fingerprints from 73,000 known and suspected terrorists. That means that a large chunk of these fingerprints was 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.

Why Do Websites Use Browser Fingerprinting?

Now, you might be wondering: why do websites browser-fingerprint you, 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 they allow 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, the bank can potentially identify a hacker who logged into the account using a device that had never accessed the account before.

All of these signs suggest potential fraud and usually trigger a further investigation or the preventative freezing of an account.

Methods 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

Cookies & Tracking

A common way for websites to obtain your data is by using cookies. Cookies are small packets of text files that your computer stores, 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 15, it will provide you with the best settings for your iPhone 15. Also, this way, the website knows whether you’re a unique or returning visitor. Cookies also store data on browsing activity, habits, interests, and much more.

Furthermore, websites employ Javascript, which will interact with visitors 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 <canvas> element was used to draw graphics on a web page.

Wikipedia provides the following explanation of 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” or “Cover Your Tracks” to test the identity of your device.

Both 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 “SEE MY FINGERPRINT” to run the test.

Am I unique

Browser Fingerprinting Screenshot 2

My browser is unique among all the test samples they’ve gathered so far (more than 2.452 million).

You can also run a test with “Cover Your Tracks”. It’s a research project of the Electronic Frontier Foundation (EFF).

On the Cover Your Tracks website, click “Test Your Browser” to run the test to see how safe your browser is against tracking.

Browser Fingerprinting Screenshot 3

Panopticlick also runs various tests to assess your browser identity. I’ve published my test results below.

Panopticlick tests whether your browser:

  1. Blocks tracking ads
  2. Blocks invisible trackers
  3. Blocks “Whitelisted” trackers
  4. Unblocks sites that promise to honor “Do Not Track”
  5. Is, overall, protected against browser fingerprinting

Browser Fingerprinting Screenshot 4

As shown in the analysis, the results are not good. I am not protected against web tracking. My browser has a unique fingerprint, making me easy to track across the web.

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 AdsPower

AdsPower allows you to avoid revealing your real browser fingerprints by allowing you to use separate browser environments, providing protection for your privacy and anonymity. The service offers a free level of service, which allows you to use two separate profiles. Also available are paid levels of service, offering more profiles for your use.

AdsPower allows users to bypass the tracking and security mechanisms of websites, create profiles that use cookies or username/password authentication, multiple fingerprint configurations, mobile browser profiles, and more.

Additional paid features include team collaboration, profile sharing, an application library with extensions, a local API, importing and exporting, auto-matching proxies, automation of routine browser tasks, and much more. These additional features – while requiring a paid subscription – are an excellent way for teams to manage and control Facebook ads and tracking.

You do get a chance to try all of AdsPower’s feature set, thanks to a seven-day trial period that allows your free account to access the features offered by the paid levels. I’ve found that the nominal fee requested by the company is well worth it for the benefits you gain.

For more information and to subscribe, visit the AdsPower website.

Use Private Browsing Methods

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 PlusPrivacy BadgerDisconnect, and NoScript are designed to block scripts that potentially enable spying ads and invisible trackers from running in your browser.

For some websites, 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 also makes 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

Browser Fingerprinting Screenshot 6

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. It also scans for any malware that may be lurking in files on your hard drive.

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 to enable automatic daily, weekly, or (at least) monthly full-system scans.

Use the Tor Browser

Tor Browser Logo

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. Since 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 the Mullvad Browser

VPN provider Mullvad now offers a browser that it developed in cooperation with the Tor Project. The Mullvad Browser is a free download and you are not required to subscribe to Mullvad’s VPN services. The browser is designed to minimize tracking and fingerprints.

As you can see below, the Mullvad Browser does an excellent job of protecting against web tracking.

cover your tracks

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 middleman. 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.

VPN Info Flow

Using a VPN is a very effective method to hide your IP address because the web server can only see the IP address of the VPN (which many other users use as well).

But, your IP address is only one aspect of your online identity.

Regardless of what IP address the web server can see, a VPN can’t block out your browser settings, version, and so forth, which generates unique browser fingerprinting data.

That means that the data of your browser still allows the web server 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 article, “What Is A Virtual Private Network (VPN) And What Does It Do?” for more information.

Using a VPN in conjunction with a private browser like Mullvad Browser provides excellent protection against browser fingerprinting.

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.

  1. Use incognito mode
  2. Implement security plugins
  3. Disable JavaScript and Flash
  4. Install anti-malware tools
  5. Use the Tor Browser
  6. Use a VPN

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.

Stop Web Tracking

What is 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 enable spying ads and invisible trackers from running in your browser.

Is a Browser Fingerprinting Test Available?

Various online tools are available to test your browser identity. You can use “Am I Unique” or “Cover Your Tracks” to test the identity of your device.

Do Any Browsers Automatically Block Browser Fingerprinting?

Firefox and Tor both employ techniques for blocking browser fingerprinting. Both browsers require websites to ask for user permission before collecting data.

Is Browser Fingerprinting Legal?

Yes, at the time of this writing, browser fingerprinting is legal in most areas of the world. There are some caveats in various countries. For example, the European Union’s General Data Protection Regulation (GDPR) requires companies to get consent from a user before tracking them using browser cookies. An additional layer of regulation, the ePrivacy Regulation, is supposed to address browser fingerprinting. However, it has not yet come into effect.

What Is Cross-Browser Fingerprinting?

Cross-Browser Fingerprinting allows sites to track users across multiple browsers, and it is also more accurate than single-browser fingerprinting.

While this can be beneficial, for example, a banking site could use it to determine that a person logging into an online account isn’t using the computer that has been used on every previous visit, which could then raise a red flag security-wise. However, it can also be used to violate a user’s privacy by being used to serve up customized ads across all of the browsers a user accesses.

What Types of Fingerprinting Technologies Do Websites Use?

While users may think of browser fingerprinting as using browser cookies to track you across the web, it is a different technology. Browser fingerprinting uses scripts to track your activity across multiple websites. Most sites that practice browser fingerprinting use scripts to track your internet travels. While you can delete cookies to foil that tracking method, you cannot delete your browser fingerprint.

Scripts can find out a lot about a user’s device, including its operating system, which browser is being used, what software is installed on a device, the user’s timezone, whether an ad blocker is being used, and much more. With enough information, browser fingerprinting scripts can track you, wherever you travel on the web. Device fingerprinting is able to identify users with 90-99% accuracy.

Is Online Fingerprinting the Same as Tracking Cookies?

While online fingerprinting can be used to track you online just like tracking cookies, they are two different technologies. While most legitimate websites will inform you when they use tracking cookies (indeed, in some countries, they are required), sites that use fingerprinting are not beholden to similar requirements.

Why Is Browser Fingerprinting Used?

Browser Fingerprinting is used mostly to track users’ online activity. The scripts that are used can pinpoint your geographic location, as well as what you’ve searched for. This information can be used to adjust the pricing of online sale items due to your location. Search results are also tracked, meaning any health-related searches you perform could be used by life and health insurers to set premiums.

Some browsers, like Brave, randomize data every time you visit a site, so your “fingerprint” is always changing and can’t be used to track you consistently. Others, like the Tor Browser, make all users look the same, which makes it difficult for websites to distinguish between individual users. Using an anti-fingerprinting browser is pretty straightforward. You need to choose one that fits your privacy needs. While these browsers can significantly enhance your privacy, no solution is foolproof, and some tracking may still occur through other means.

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