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Visitor Identification at Scale

Enterprise-ready, GDPR-compliant browser identification - without the enterprise price tag.

Visitor ID: -

First seen

-

Last seen

-

Bot

No

VPN

No

Threat level

-

-

Integrate in Seconds

Install, generate an API key, and start identifying visitors in minutes.

Get the code

Open-source SDK on GitHub. Browse the source and examples.

Get the code →

Install from NPM

Install with one command. Works with modern JS frameworks.

Install via npm →

Load from CDN

Use ThumbmarkJS instantly—no build step required.

Load from CDN →

Join Discord

Get help, share feedback, and talk directly with maintainers.

Join Discord →

Get API key

Create a free account and start identifying visitors.

Get API key →

See Thumbmark in Action

Run the snippet and watch the same visitor ID persist across refreshes, tabs, and private mode.

1// just a few lines of code in javascript console
2import('https://cdn.jsdelivr.net/npm/@thumbmarkjs/thumbmarkjs/dist/thumbmark.umd.js')
3.then(() => {
4  const tm = new ThumbmarkJS.Thumbmark();
5  tm.get().then((t) => { console.log(t.thumbmark)})
6})
7// prints out a 32 character fingerprint like 00c8328e409c4831e4aba4f65ec3a0c1

6B identifications / month

Proven at internet scale

600M jsDelivr hits / month

Immensely popular

400k+ NPM downloads

High developer adoption

Trusted by developers at +60,000 websites

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