Passkeys vs Passwords: What's the Difference?

Passwords have been the default way to sign in for so long that we rarely question them — yet they're simultaneously hard to remember and easy to steal. A passkey is a newer approach that aims to be both stronger and less effort. This is a plain-English comparison of the two, without unnecessary technical detail.

Passwords

A password is a shared secret: you and the service both know it, and you prove who you are by typing it in. The weaknesses follow directly from that:

• They can be guessed, leaked or phished.
• They get reused across sites, so one breach can open many accounts.
• They have to be remembered, which pushes people toward weak or repeated passwords.

Password managers and two-factor authentication help a great deal, and they remain good practice today. But they're improvements on top of a fundamentally fragile system.

Passkeys

A passkey is a way to sign in without a password. Instead of a shared secret, it uses a pair of cryptographic keys: one stays on your device, the other is registered with the service. When you sign in, your device proves it holds the private key without ever sending it anywhere.

You don't see or type the key. You just confirm, much like unlocking your phone.

The basic idea, without the maths

Think of it as a handshake rather than a password. The service sends a challenge; your device signs it using the private key; the service checks the signature against the public key it holds. At no point is a secret transmitted that someone could steal and replay.

The practical upshot: there's no password to phish, leak, guess or reuse. The thing that gets attacked in a traditional password scheme simply isn't there.

Biometrics

This comes up a lot, and it's worth being clear: biometrics (your face or fingerprint) are not sent to the service. They're used locally, by your device, to unlock the passkey and authorise the sign-in. The website never sees your fingerprint. Biometrics here are a lock on your device, not a credential travelling across the internet.

Phishing resistance

This is one of the biggest practical differences. A password can be typed into a fake login page that looks real. A passkey is bound to a specific service, so when you're sent to a lookalike site, the passkey simply doesn't work for it — the mismatch is detected before anything is handed over. That neutralises a huge proportion of phishing attacks automatically, without you having to spot the fake.

Syncing passkeys

Modern passkey implementations can sync across your devices through your account with the platform provider, so a passkey created on your phone is available on your laptop. This is convenient and, for most people, a reasonable trade-off — it keeps the security benefits while making passkeys usable across devices. Some platforms also let you keep a passkey only on a single device or a security key if you prefer not to sync.

The key point: even when synced, there's still no shared secret the service can leak. The model is different from a password stored in the cloud.

Recovery

People reasonably worry about what happens if they lose their device. Because passkeys sync across your account, losing one device usually doesn't lock you out — the passkey exists on your other devices. Services also provide account recovery paths, often including another signed-in device, a recovery key or, where appropriate, a fallback method. The exact options vary by service, which is why it's worth setting up more than one signed-in device when you can.

Should you use passkeys when offered?

In most cases, yes. When a service offers a passkey, you gain stronger security and remove a password you'd otherwise have to manage, with phishing resistance built in. The experience is usually quicker than typing a password and waiting for a code.

A few sensible habits:

• Set up passkeys on more than one device where you can, so losing one doesn't lock you out.
• Keep a strong fallback method for account recovery.
• Where a service still uses passwords, pair them with two-factor authentication and a password manager.

You don't have to switch everything at once. Start with the services that matter most, and add passkeys as they're offered. If you'd like a fuller walkthrough, The Password Guide covers the practical setup in detail, and The Digital Security Guide places it in the wider context of everyday account security.