What is Passkey
⚡ 8 min readImagine logging into your favorite app just by looking at your phone or touching a fingerprint sensor. No typing passwords, no remembering complicated strings of letters and numbers. That’s what a passkey does.
The Simple Explanation
Think of a passkey like a magic key that only works with your face or fingerprint.
| Old Way (Passwords) | New Way (Passkeys) |
|---|---|
| Type “MyP@ssw0rd123!” every time | Just look at your phone or touch the sensor |
| Remember dozens of different passwords | Your face or fingerprint is the only “password” |
| Can be stolen by hackers | Cannot be stolen - it’s part of YOU |
| Can be guessed or cracked | Impossible to guess your fingerprint |
In one sentence: A passkey lets you log in with your fingerprint or face instead of typing a password.
Why Passwords Are a Problem
Password Frustration
- “What was my password again?”
- “Please include uppercase, lowercase, numbers, and special characters”
- “Your password has expired. Please create a new one.”
- “Incorrect password. 2 attempts remaining.”
The Security Problem with Passwords
Passwords are the weakest link in modern security:
| Problem | Impact |
|---|---|
| Password Reuse | 65% of users reuse passwords across sites |
| Phishing Attacks | $17,700 lost per minute globally |
| Credential Stuffing | 193 billion attacks in 2020 alone |
| Support Costs | 20-50% of helpdesk calls are password resets |
81% of hacking-related breaches leverage stolen or weak passwords. (Verizon Data Breach Report)
How Passkeys Make Everything Better
It’s Incredibly Simple
| Action | With Passwords | With Passkeys |
|---|---|---|
| Log in | Type password, maybe get it wrong, try again | Touch sensor or look at camera. Done. |
| Sign up | Create password, confirm password, verify email | Touch sensor or look at camera. Done. |
| Forgot access | Reset password, check email, create new password | Just use your fingerprint again |
It’s Actually Secure
Here’s the magic: your passkey never leaves your device.
When you use a password, you send it to the website. If that website gets hacked, your password is stolen.
When you use a passkey, you never send anything secret. Your device just proves “yes, this is really me” without revealing how. It’s like showing your ID without giving away your ID.
| Passwords | Passkeys |
|---|---|
| Stored on websites (can be hacked) | Stored only on YOUR device |
| Can be phished with fake sites | Won’t work on fake sites |
| Can be guessed | Nothing to guess |
| Can be shared (and stolen) | Cannot be copied or shared |
It’s Fast
- Password login: 10-30 seconds (if you remember it)
- Passkey login: 1-2 seconds
Who Uses Passkeys
Every major tech company now supports passkeys:
| Company | Status |
|---|---|
| Apple | Built into iPhone, iPad, Mac |
| Built into Android, Chrome | |
| Microsoft | Built into Windows |
| Amazon | Passkey login available |
| PayPal | Passkey login available |
| GitHub | Passkey login available |
By 2027, 75% of all online accounts are expected to use passkeys instead of passwords.
How It Works (The Non-Technical Version)
Setting Up a Passkey
- You visit a website and click “Create Passkey”
- Your phone asks for your fingerprint or face
- Your phone creates a special “key pair” - one part stays on your phone (secret), one part goes to the website (public)
- Done! You now have a passkey for that site
Using Your Passkey
- You visit the website and click “Log in”
- Your phone asks for your fingerprint or face
- Your phone proves “yes, this is the real owner” using the secret key
- You’re logged in!
The important part: Your secret key NEVER leaves your phone. The website only ever sees proof that you’re you, not the actual key.
Passkeys Work Everywhere
| Device | How You Authenticate |
|---|---|
| iPhone / iPad | Face ID or Touch ID |
| Mac | Touch ID or Apple Watch |
| Android | Fingerprint or Face Unlock |
| Windows | Windows Hello (fingerprint, face, or PIN) |
| Any Device | Physical security key (like YubiKey) |
Your passkeys sync across your devices automatically:
- Apple devices: Through iCloud Keychain
- Android/Chrome: Through Google Password Manager
- Windows: Through Microsoft account
Note: Passkeys require a secure connection (HTTPS). This is automatic on all real websites.
But, WebAuthn Implementation is Hard
WebAuthn could solve the password problem, but correct implementation is complex:
Configuration & Registration
- Generate cryptographically secure challenges
- Configure authenticator selection criteria
- Handle attestation verification
- Store credential public keys and metadata
Authentication
- Generate and manage challenges with proper timeouts
- Retrieve stored credentials
- Verify assertion signatures
- Handle user verification flags
Infrastructure Setup
- Backend SDK integration
- Database schema for credentials
- Session management
- Token issuance and refresh
Edge Cases
- Browser compatibility differences
- Cross-device authentication flows
- Credential recovery mechanisms
- Error handling and user feedback
Quick Terminology
Just in case you hear these terms:
| Term | What It Means |
|---|---|
| Passkey | Your fingerprint/face login credential |
| WebAuthn | The technology that makes passkeys work in browsers |
| FIDO2 | The industry standard behind passkeys |
| Authenticator | The device that verifies you (your phone, laptop, etc.) |
| Biometrics | Fancy word for fingerprint or face recognition |