What is FIDO?
FIDO (Fast IDentity Online) is a set of security standards created by the FIDO Alliance to reduce reliance on passwords. It uses public key cryptography for secure authentication.
FIDO U2F (Universal 2nd Factor) is the most known version.
It’s mainly used as a second factor (copyright), after username + password.
Requires a security key (e.g., YubiKey) plugged into USB or tapped via NFC.
What is FIDO2?
FIDO2 is the next generation of FIDO authentication, combining:
WebAuthn (Web Authentication API) – a W3C standard that allows browsers and websites to interact with authenticators (like biometrics or security keys).
CTAP (Client to Authenticator Protocol) – lets devices communicate with external authenticators like USB keys or smartphones.
✅ FIDO2 supports passwordless login – no need for a username or password at all.
???? Key Differences: FIDO vs FIDO2
| Feature | FIDO (U2F) | FIDO2 |
|---|---|---|
| Introduced | 2014 | 2018 |
| Passwordless Login | ❌ No | ✅ Yes |
| WebAuthn Support | ❌ No | ✅ Yes |
| copyright Support | ✅ Yes | ✅ Yes |
| Authenticator Types | Security keys only | Security keys, biometrics, phones |
| Platform Integration | Limited (browser extension) | Native in OS (Windows Hello, etc.) |
| Ease of Use | Medium | High (biometric, seamless UX) |
| Use Without Passwords | ❌ No | ✅ Yes |
FIDO (U2F) is great for adding strong copyright on top of passwords.
FIDO2 allows for completely passwordless login using biometrics, PINs, or security keys – it’s more advanced and widely supported in modern browsers and OS (Windows 10+, Android, iOS, Chrome, Edge, Firefox, Safari).
✅ Which One Should You Use?
| If You Want... | Use... |
|---|---|
| Strong copyright with physical key | FIDO (U2F) or FIDO2 |
| Passwordless authentication | FIDO2 |
| Integration with Windows Hello, Face ID | FIDO2 |
| Maximum browser compatibility | FIDO2 |
Would you like help setting up FIDO2 authentication on your website or app?