Browser Fingerprinting

What Is It and What Should You Do About It?

scan fingerpring on laptop

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.”

Device 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 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 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 is 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.

1

Cookies & Tracking

What Are Cookies?

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.

2

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 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.

3

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.

Am I Unique Browser Fingerprint Test
Am I Unique Browser Fingerprint Test Results

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 Browser Fingerprint Test

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

Panopticlick Browser Fingerprint Test Results

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.

1

Use Private Browsing Methods

Incognito Browser

Various browsers like Chrome, 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.

2

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 script that potentially enables 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.

3

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.

4

Install Anti-Malware Software

HitmanPro AntiMalware Scan Results

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.

5

Use the Tor Browser

Tor 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. 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.

6

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 web server.

How Does a VPN Work

Using a VPN is a very effective method to hide your IP address, because the web server 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 what IP the web server 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 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 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.

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

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.

Panopticlick Browser Fingerprint Uniqueness Test

So, now you know how to protect yourself against browser fingerprinting. If you have any questions, please let me know in the comment section below!