FingerprintJS: How It Blocks Web Scrapers

FingerprintJS is best known as the open-source library that turns a browser's characteristics into a visitor ID. The company behind it, Fingerprint, sells a commercial version, Fingerprint Pro, that identifies visitors far more accurately and adds signals for bots, headless browsers, VPNs and tampering.

FingerprintJS is not in our benchmark yet. None of the targets we scrape every month shows it. So there is no success rate, speed or cost to rank here. When a target that FingerprintJS blocks joins the benchmark, this page will rank web scraping APIs against it the same way as our Cloudflare and AWS WAF CAPTCHA pages.

How FingerprintJS detects bots

A visitor ID from device signals. The script reads hundreds of browser and device properties (graphics, audio, fonts, screen, language and more) and combines them on Fingerprint's servers into an ID that stays the same across cookie clearing and incognito windows.

Bot and tampering signals. Fingerprint Pro's Smart Signals flag automation tools and headless browsers, browsers whose properties have been changed to hide them and traffic through VPNs and proxies.

The site decides. Fingerprint doesn't block anything by itself. The site's server reads the visitor ID and signals and decides whether to serve the page, ask for another check, or refuse.

Scraping APIs and FingerprintJS

Fingerprinting rewards consistency. A scraper whose browser properties match each other and a real device, and don't change between requests in odd ways, looks like an ordinary visitor. Spoofed or randomised fingerprints are exactly what its tampering signals look for.

Frequently asked questions about FingerprintJS

Which web scraping API is best for FingerprintJS?

We don't know yet, because none of our benchmark targets shows FingerprintJS. We only publish rankings we have measured.

Is FingerprintJS an anti-bot?

It identifies visitors and flags bots, headless browsers and tampering. Blocking is left to the site that uses it.

What is the difference between FingerprintJS and Fingerprint Pro?

FingerprintJS is the open-source library. Fingerprint Pro is the commercial service from the same company, with more accurate identification and bot, VPN and tampering signals.

Benchmarked anti-bots: Cloudflare · Akamai · DataDome · PerimeterX · Kasada · AWS WAF CAPTCHA · Castle  ·  Hub: All anti-bot benchmarks