One of the most significant ways you leak private data while using the internet is through your browser. No VPN can help you; this is largely unconnected to the service they provide.

But what information precisely is being logged? Here are 10 types of data that your browser is (probably) collecting about you.

1. Hardware and Software

Your browser collects data about your hardware and software.

In terms of software, your browser knows your operating system, IP address, browser, and browser plugins. From a hardware standpoint, your browser collects information about your CPU, GPU, and battery.

To restrict the amount of hardware and software data that your browser leaks, use a privacy-focused plugin like NoScript.

2. Connection Information

Your browser knows about your connection to the web. That information includes your IP address and browser speed.

3. Geolocation

geolocation prediction from browser

A website can accurately estimate your location, even if you've not given it access to your GPS coordinates. Instead, it can use the Google GeoLocation API. Even if you're accessing the web from a browser on a mobile device, it will be accurate to within 30 miles.

To stop your browser from leaking your location data, you can use a web proxy to access sites. There lots of free options available.

To stop browsers from using services like Google GeoLocation, you'll need to disable JavaScript. Again, apps like NoScript can do it for you automatically.

4. Browsing History

The most well-known data your browser collects about you is your browsing history.

Of course, you can delete your browsing data. But even then, it might not be truly gone for good. For example, in mid-2018, it emerged that Google maintains records about the way you used Chrome in relation to the deleted data, even if the specifics of the data have been wiped.

We've explained how to delete your browsing data on Edge, Chrome, and Safari. You can also delete cookies on all the major browsers.

5. Mouse Movements

clickclickclick results page

Your browser can even reveal your mouse movements and clicks to websites. To see it action, have a play around with ClickClickClick's free tool.

6. Your Device's Orientation

These days, lots of smartphones come with built-in gyroscopes. They're used in fitness tracking apps and similar movement-based services.

This data is collected in your browser. It knows whether your device has a gyroscope, a compass, which orientation it is currently in, and a few other technical details.

Your browser can even predict where your device physically is right now, such as on a table, in a bag, or in a pocket.

7. Social Media Logins

Your browser collects information about which social networks you are logged into while browsing the web.

The app can correlate that information which other data points so advertisers know where and how to target you for the maximum impact.

8. Fonts and Language

browser technical data collected

Your browser knows which fonts are installed on your machine, and which language you are using on your operating system.

9. Image Data

Whenever you upload an image using your browser, it will scan the file's metadata to learn about you.

The metadata can include information such as location, image resolution, technical specs of the file, and even the camera model that you used to take a photograph.

10. Technical Information

In addition to the points we've discussed above, your browser also collects massive amounts of technical data about the way you're accessing the web.

The data includes your user agent, touchscreen support, whether the Do Not Track (DNT) header is enabled, your screen size, and more.

Checking What Data Your Browser Is Collecting

With so much of your data potentially at risk, it's wise to do an audit every now and again. It lets you stay on top of what's leaking and take remedies to fix it.

There are two web-based tools worth checking out. Both are free.

1. Webkay

Webkay is a test site. It scans your current browser to find what information it knows about you that could be shared with other sites.

For each category, you will see the result along with some recommendations about how to fix the issue.

2. Panopticlick

Panopticlick results page

Panopticlick is a tool from the Electronic Frontier Foundation (EFF). It scans your browser and establishes whether you're at risk from "non-consensual web tracking".

It can send your data to a real tracking company to test whether your privacy software's whitelists are letting certain organizations bypass your setup without your knowledge.

However, this web app really shines thanks to its fingerprinting tool. It aims to show you how unique your current browser's fingerprint is.

As you can see from the picture above, my browser was unique among the 2.2 million that the tool had tested in the previous 45 days.

If you try this tool out, you can see the full results by clicking on Show full results for fingerprinting.

Browser Extensions Also Collect Data

Let's not forget that there are many browser extensions and add-ons that collect information about you.

One of the most notorious examples is the Chrome Web Store. In June 2018, Adguard co-founder Andrey Meshkov discovered that dozens of the store's most popular extensions are tracking users.

The extensions start to scrape data as soon as you launch your browser. They target Facebook posts, sponsored posts, tweets, YouTube videos, and ads that you have interacted with. In his accompanying blog post, Meshkov said the extensions even try to parse your Facebook purchase history.

The four extensions flagged by Adguard were:

  • Video Downloader For Facebook (180,000 users)
  • PDF Merge: PDF Files Merger (100,000 users)
  • Album & Photo Manager For Facebook (130,000 users)
  • Pixcam: Webcam Effects (35,000 users)

That's almost 500,000 affected people!

Of course, if these four common extensions are collecting your data, you can be confident that thousands of lesser-known extensions are doing exactly that same thing.

As always, the advice remains the same. Do your due diligence, don't install more extensions than you need, and don't download extensions from companies you don't trust.

Obscure Your Web Fingerprint With These Tips

Even though your browser will not collect or distribute any personally identifying information, it is still possible for companies to infer much about your identity, thanks to your browser fingerprint.

You should take as many steps as possible to obscure your fingerprint. That includes using a private browser and running the best security extensions.