Know every visitor.
Even the ones hiding.
Prynt gives every browser a stable visitorId with a confidence score, plus bot, incognito, VPN and network signals. A better, self-hostable device-intelligence platform.
import Prynt from '@prynt/js';
const prynt = await Prynt.load({ apiKey: 'pk_live_…' });
const { visitorId, confidence } = await prynt.identify();
// → vst_9k2f… · 98.5% high The signals other tools gate — all included
Free browser-fingerprint SDKs stop at a fragile hash. Identity, confidence and risk live behind a paywall. Prynt ships all of it.
Stable visitor IDs
Server-side matching fuses 20+ entropy signals into one identity that survives cookie clears, incognito, and signal drift.
Confidence scoring
Every match ships a calibrated 0–100% score, so you decide exactly how much to trust it per action.
Bot & automation defense
Headless Chrome, Selenium, Puppeteer, Playwright — caught server-side from raw tells, never spoofable booleans.
Network & IP intelligence
VPN, proxy, Tor, datacenter and residential-proxy exits, with ASN, reputation and geo — resolved at the network layer.
npm or a single tag
A 14 kB zero-dependency agent. Install from npm or drop in one script tag. No build step required.
Yours to host
MIT-licensed. Run it on your own infrastructure and own 100% of your visitor data. No lock-in, ever.
Enterprise-tier capability, without the enterprise invoice
| Capability | OSS fingerprint | Commercial Pro | Prynt |
|---|---|---|---|
| Server-side matching | |||
| Confidence score | |||
| Bot & headless detection | |||
| VPN / Tor / datacenter signals | |||
| Residential-proxy detection | |||
| Self-host & own your data | |||
| Open source | |||
| Price | Free | $$$$ | Free OSS · small hosted fee |
Load the agent. Call identify. Verify server-side.
Ship device intelligence in an afternoon — then own it forever.
Guides & references
Deep-dives on the signals, threats and integrations behind modern device intelligence.
Device fingerprinting
How a stable visitorId is built from 20+ signals — and why it survives incognito.
Bot detection
Catch headless browsers, automation frameworks and AI agents, server-side.
Account takeover
Stop credential stuffing and post-login ATO with device identity and biometrics.
Prynt vs FingerprintJS
An honest, self-hosted-first comparison — feature table and migration path.
Glossary
Plain-English definitions for fingerprinting and fraud-prevention terms.
SDKs
Browser, server (7 languages), mobile (4) and edge connectors.
Frequently asked questions
What is Prynt?
Prynt is an open-source, self-hostable device intelligence platform. It gives you a stable visitor ID with a confidence score, plus bot, VPN, proxy and fraud Smart Signals — the open-source alternative to FingerprintJS Pro that runs on your own infrastructure.
How is device fingerprinting different from cookies?
A cookie is storage you set that a user can clear in one click. A device fingerprint is derived from the device itself — GPU rendering, hardware, fonts, network — so the same visitorId persists across cookie clears and incognito. See our device fingerprinting guide.
Is Prynt accurate enough for fraud prevention?
Yes. Prynt fuses 20+ signals server-side, ships a calibrated confidence score, and layers behavioral biometrics, JA4 TLS fingerprinting and a reputation network on top — so you can set precise risk thresholds per action.
Can I self-host and keep my data?
That is the point. Prynt is MIT-licensed and self-hostable, so raw visitor data — IPs, fingerprints, behavior — never leaves your infrastructure. No per-API-call pricing, no vendor lock-in.
How do I migrate from FingerprintJS?
The browser agent mirrors the familiar load() / get() shape, so migration is mostly swapping the script URL and endpoint. See the migration guide for a side-by-side, and the comparison for a full feature table.
Does Prynt detect bots and AI agents?
Yes. Prynt catches headless Chrome, Selenium, Puppeteer and Playwright from raw server-side tells, and classifies AI-agent traffic (ChatGPT Operator, Perplexity, GPTBot and more) as a distinct verdict.