JavaScript agent placement

The JS agent is a client-side JavaScript snippet that collects browser attributes and sends these signals to Fingerprint servers for processing and identification. Depending on your use case, the placement of this script can range from all pages of your app to specific pages and events.

Fingerprint billing is based on API usage (device identifications), so it is important to make the most of your applications’ monthly API limit. We recommend calling the API only when the visitorId will be processed or saved by your application.

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Using a JavaScript framework?
We offer framework-specific libraries for React, Next, Vue, Svelte, Preact, and Angular with a built-in visitorId caching mechanism. Use one of our frontend libraries to cache visitor identifiers and reduce the number of API requests.

The table below lists common use cases and recommended integration of the JavaScript agent.

Use Case	JS Agent Placement	API Call Event	Estimated Volume (per month)
Anonymous Visitor Identification - bulk information collection of anonymous visitors	Landing page, checkout page, etc.	Page load or start of session (depending on your implementation)	1:1 number of page loads/sessions
Account Takeover Prevention - prevent account theft from malicious login attempts	Login page	"Login" button click	1:1 number of attempted logins
Securing Login & Reducing Friction - reduce friction with conditional security checks at login	Login page	"Login" button click	1:1 number of attempted logins
Account Sharing Prevention - prevent users from sharing accounts	Login page	"Login" button click	1:1 number of attempted logins
Multi-account Prevention - prevent users from creating multiple accounts	Registration page	"Register" button click	1:1 number of attempted sign ups
Form & Survey Abuse - protect forms from duplicate entries	Form page	“Submit Form” button click	1:1 number of attempted form submissions
Coupon & Promo Abuse - protect profits from duplicate promotion abuse	Checkout page	“Apply coupon” button click	1:1 number "apply coupon" button clicks
Credit Card Fraud - block users who repeatedly use faulty credit cards	Checkout page	“Checkout” button click	1:1 number of checkout attempts
E-commerce Tracking - track orders made by anonymous visitors	Checkout page	“Checkout” button click	1:1 number of checkout attempts
Paywall Circumvention - detect Incognito mode and prevent unlimited views of your paywalled content	Paywalled pages	Page load	1:1 number of paywalled page loads

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Device fingerprinting for native mobile apps
For mobile device identification, we highly recommend using our native SDKs for Android and iOS. For device identification that is scoped to the browser instance, a unique ID called visitorId is generated per browser. If a visitor switches to a different browser on the same device, a new visitorId is generated for that browser.