Skip to content
Know.itKnow.it
Create an animated lesson
On request

This article is free to read. Creating a lesson uses your daily or stored credits; review the language and settings before starting.

How does a fingerprint scanner work?

TechnologyLesson on requestFree to read

Quick answer

A fingerprint scanner works by capturing the unique pattern of ridges on your fingertip and comparing it to a stored version. It reads the tiny hills and valleys of your print, turns them into data, and checks for a match to unlock a device.

Step by step

  1. It images the ridges and valleys of your fingertip.
  2. Capacitive scanners sense the pattern electrically; optical ones photograph it.
  3. Software extracts distinctive points and converts them to a template.
  4. Each scan is matched against the stored template, not a raw image.
  5. The template is encrypted and stored securely on the device.

People also ask

How does a phone recognize your fingerprint?
It maps the unique ridge pattern into a mathematical template and checks whether a new scan matches the one stored securely on the device.
Is your actual fingerprint image stored?
Usually not — devices store an encrypted mathematical template, not a picture, and keep it in a protected area of the chip.
Can two people have the same fingerprint?
Effectively no; fingerprint patterns are unique enough that a match is overwhelmingly likely to be the same person.