ThumbmarkJS
Enterprise-ready, GDPR-compliant visitor identification - without the enterprise price tag.
Overview
Most of this category is priced on the last decimal point of accuracy. That decimal is expensive, and for most uses it changes nothing. We charge a fraction of the going rate for accuracy that covers the large majority of use cases. If you need hard real-time blocks on financial transactions with no human review, buy the expensive one. We will say so.
Enough teams have made that trade that ThumbmarkJS now runs on 60,000+ websites and is the fastest growing browser fingerprinting library on npm.
Three kinds of team use it.
Attribution and adtech. Stitching a visitor's journey across domains, where a third-party cookie no longer survives the hop. Same browser, different domain - not a different browser, and not a different device. This is the heaviest use of the API today.
Fraud and risk. Fake signups from one browser, payment and refund abuse, account takeover, promo abuse, scraping and bots.
Product and growth. Recognizing logged-out returning visitors - persistent carts, metered paywalls, personalization without a cookie.
Thumbmark is an open-source browser fingerprinting tool designed for fraud prevention, analytics, and personalization, emphasizing cookie-free operation.
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- TaglineEnterprise-ready, GDPR-compliant visitor identification - without the enterprise price tag.
- Founder-editedDate not recordedSource link unavailable
- DescriptionMost of this category is priced on the last decimal point of accuracy. That decimal is expensive, and for most uses it changes nothing. We charge a fraction of the going rate fo...
- Founder-editedDate not recordedSource link unavailable
- Free planYes
- Founder-editedDate not recordedSource link unavailable
- Free trialNo
- Founder-editedDate not recordedSource link unavailable
- Pricing modelopen_source_plus_hosted
- Founder-editedRecorded Source link unavailable
- IntegrationsReact, Preact, Angular, Vue
- Founder-editedDate not recordedSource link unavailable
- Founded2025
- Founder-editedRecorded Source link unavailable
- Headquarters countryFI
- Founder-editedRecorded Source link unavailable
- Headquarters cityEspoo
- Founder-editedRecorded Source link unavailable
- Plan: Open SourceFree
- Founder-editedRecorded Source link unavailable
- Plan: Free APIFree
- Founder-editedRecorded Source link unavailable
- Plan: Pro€15/mo
- Founder-editedRecorded Source link unavailable
- Plan: EnterpriseCustom
- Founder-editedRecorded Source link unavailable
- SummaryThumbmark is an open-source browser fingerprinting tool designed for fraud prevention, analytics, and personalization, emphasizing cookie-free operation.
- Founder-editedDate not recordedSource link unavailable
Pricing
- Runs locally in the browser, without API calls.
- ~80% uniqueness.
- For testing & small projects.
- 1K calls per month with ~99% uniqueness.
- For larger projects.
- 15K calls per month, then 1€ per additional 1K calls.
- Volume discounts, custom SLAs, compliance & flexible terms.
Who Is It For
Developers and businesses seeking a flexible, open-source solution for visitor identification without reliance on cookies.
Organizations looking for a comprehensive commercial support package or extensive built-in analytics features.
Strengths & Weaknesses
Alternatives to ThumbmarkJS
Community
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