--- title: "FingerprintJS alternatives compared: TraceTail, Fingerprint, ThumbmarkJS and ClientJS" description: "Browser fingerprinting libraries and APIs compared on price at 10,000 to 1 million requests a month, free tiers, licenses and server-side verification, from each vendor's published pages as of October 5, 2026." url: https://tracetail.io/fingerprintjs-alternatives updated: 2026-10-05 --- Comparison · checked October 5, 2026 # FingerprintJS alternatives FingerprintJS is the best-known browser fingerprinting library. These are the tools developers compare it with, from open-source libraries that run in your pages to APIs that register identifications and let your server verify them, with prices from each vendor's published pages. ## At a glance | Tool | What it is | Free | Server-side verification | License | | ----------------- | ---------------------------------------------- | ------------------------------------------- | --------------------------------------------------------------------- | -------------------------------- | | TraceTail | Browser fingerprinting API (script tag or npm) | 1,000 requests a month; keyless use is free | Yes: Server API with secret server keys | Hosted service; MIT-licensed SDK | | Fingerprint (Pro) | Device intelligence platform | 1,000 web API calls a month | Yes: Server API | Commercial | | FingerprintJS | Open-source browser library | Free: runs in your pages | No: IDs are computed in the browser only | MIT (since 5.0.0) | | ThumbmarkJS | Open-source library with a paid API | Library free; API 1,000 calls a month | With the API, results are posted to your server afterwards; no lookup | MIT (library) | | ClientJS | Open-source browser library | Free: runs in your pages | No: IDs are computed in the browser only | Apache-2.0 | ## Monthly price by volume What each hosted API costs at list price for the identification requests a month shown. The open-source libraries cost nothing to run but have no API behind them. | API | 10,000 a month | 100,000 a month | 1,000,000 a month | | ----------------- | -------------- | --------------- | ------------------- | | TraceTail | $0.90 | $9.90 | $99.90 | | Fingerprint (Pro) | $99.00 | $419.00 | Custom (Enterprise) | | ThumbmarkJS | €15 + VAT | €100 + VAT | €1,000 + VAT | ## The tools ### TraceTail Browser fingerprinting API (script tag or npm) A stable visitor ID with over 99.5% accuracy, the same in normal and incognito windows, without cookies. The SDK runs keyless with no sign-up; with a key, identifications are registered, checked for automation and verifiable from your server. 1,000 requests are free every month, then $0.10 per 1,000 at every volume. Choose it when you want an API with server-side verification at a per-request price that stays low at volume, for web apps. [Pricing](https://tracetail.io/pricing) ### Fingerprint (Pro) Device intelligence platform The company behind FingerprintJS. Its Pro Plus plan costs $99.00 a month including 20,000 API calls, then $4.00 per 1,000, with native iOS and Android SDKs and Smart Signals such as VPN and browser-tamper detection. Free and Pro Plus allow 5 requests a second and keep data 30 days. Choose it when you need native mobile SDKs, VPN or tamper signals, or an enterprise SLA, and the price fits. [Source](https://fingerprint.com/pricing/) ### FingerprintJS Open-source browser library The best-known library. It is MIT-licensed again since version 5.0.0 (October 22, 2025); 4.x was BUSL-1.1. Its README says its accuracy is "significantly lower than in the commercial version" and that, being computed in the browser, "they are vulnerable to spoofing and reverse engineering". Choose it when you only need a rough in-browser hash, with nothing to verify on a server. [Source](https://github.com/fingerprintjs/fingerprintjs) ### ThumbmarkJS Open-source library with a paid API Its README puts the browser library at \~80% uniqueness and its API at \~99%. The Pro API plan costs €15 a month including 15,000 calls, then €1 per 1,000, excluding VAT. Choose it when you want an MIT library you can run yourself, with an optional API priced in euros. [Source](https://www.thumbmarkjs.com/pricing) ### ClientJS Open-source browser library Hashes browser traits, including the user agent, into a 32-bit number. Its last release is 0.2.1, from October 25, 2021. Choose it when you maintain a legacy integration that already depends on it. [Source](https://github.com/jackspirou/clientjs) ## Questions - Is FingerprintJS free? The FingerprintJS library is free and open source: MIT since version 5.0.0, released October 22, 2025 (versions 4.x were BUSL-1.1). Fingerprint, the company behind it, sells a separate commercial service whose Pro Plus plan starts at $99.00 a month. - What is the difference between FingerprintJS and Fingerprint Pro? FingerprintJS computes a hash in the browser and nothing else; Fingerprint's commercial product adds server-side processing, a Server API and Smart Signals. Fingerprint's README for the library says its accuracy is "significantly lower than in the commercial version". - Which FingerprintJS alternative costs least at volume? Of the hosted APIs compared here, at their published prices: 100,000 requests a month cost $9.90 on TraceTail, €100 plus VAT on ThumbmarkJS Pro and $419.00 on Fingerprint Pro Plus. The open-source libraries cost nothing but have no API behind them. - Can I check a visitor ID on my server? With an API, yes: TraceTail's Server API and Fingerprint's Server API both let your backend look up an identification before trusting it. Libraries that only run in the browser can't: the ID comes from the visitor's browser, so anyone can send any value. - How hard is it to switch from FingerprintJS to TraceTail? Replace the library with the TraceTail script tag or the @tracetail/js package and keep sending visitorId to your backend. The two compute different IDs, so each returning visitor gets a new ID once; run both side by side for a few weeks to link them. List prices from each vendor's pricing page as of October 5, 2026 (ThumbmarkJS's exclude VAT). Accuracy and uniqueness figures are each vendor's own claims. ## Start identifying visitors today 1,000 requests free every month, no credit card required. Add a card only when you need more. [Get started free](https://tracetail.io/auth) [TraceTail vs FingerprintJS](https://tracetail.io/vs-fingerprintjs)