ThumbmarkJS

ThumbmarkJS is a simple JavaScript library that creates a fingerprint hash of the browser. It is easy to use and easily extendable. While not (yet) as good, it's a free open source alternative to the market leading FingerprintJS.

This library is not very robust against trickery such as plugins that deliberately are used to trick you. The library is still under development.

ThumbmarkJS is open source (MIT).

Demo page

You can help this project by visiting the demo page that logs your fingerprint for analysis. The logged fingerprint data is only used to improve this library. Visit the page from the link below:

Show and log my fingerprint

Simple usage from CDN

<script src="https://cdn.thumbmarkjs.com/latest/Thumbmark.js"></script>
<script>
    ThumbmarkJS.getFingerprint().then(
        function(fp) {
            console.log(fp);
        }
    );
</script>

You can also call ThumbmarkJS.getFingerprintData() to get a full JSON object with all its components.

You can also get any previous version from the CDN by replacing latest with the version number. Currently the URL would be

https://cdn.thumbmarkjs.com/0.11.1/Thumbmark.js

Or build it yourself

Clone this repo and then run

npm run install
npm run build

Still under construction

Because the library is still under construction, changes might happen to it. I might need to add an init() function at some point. The components of the fingerprint might change. Obviously trying to keep this as simple as possible to take into use and avoid any unnecessary changes. But if you're planning to use this live, better to freeze to a specific version with CDN or host the file yourself.

Please help! ♥

Simply going to the page above (which logs your visit) helps a lot. It's all anonymous and only used to develop this library. Let me know if you run into any errors by opening an issue. The discussion section is also open.

Test cases you can try:

• Check your fingerprint, then refresh the page with Ctrl + R
• Refresh without cache
• Move the window to another screen
• Try in incognito

if you see a fingerprint change when it shouldn't, you can use this JSON Diff Finder tool to check what causes the diff.

Components included in fingerprint

• audio fingerprint
• canvas fingerprint
• webgl fingerprint
• available fonts and how they render
• videocard
• browser languages and time zone
• browser permissions
• available plugins
• a ton of screen details including media queries
• and a bunch of smaller things

Technical details

I wanted to create something that's easy to build, extend and use. If you're interested in how the library works, the structure is very simple.

Have a look at the technical_details