Is face unlock on a Mac safe?

The honest answer

Face unlock on a Mac is safe enough for everyday convenience in a place you trust, and not a replacement for Touch ID or a strong password. The reason is simple hardware: Mac cameras see a flat 2D image, while Face ID on iPhone uses a 3D depth sensor. Anyone telling you webcam face unlock is “as secure as Face ID” is overselling it.

What matters is knowing the trade-off, and turning on the settings that close most of the gap.

How the recognition works

Visage runs Apple’s Vision framework to find your face, lines it up, and passes it through an ArcFace-based Core ML model. The result is a 512-number embedding: a compact fingerprint of your features. It’s compared with the embeddings saved when you enrolled, and it counts as a match only above a similarity threshold you control with Match confidence.

Because you enroll in nine head positions, the saved profile covers the angles you’re likely to be at when you look at your screen.

Photos, screens and videos

Here’s how a regular camera fares against the usual tricks:

How liveness checks work

Liveness checks watch a rolling window of about two seconds for signs of a real face. They come in two kinds:

• Deny cues are evidence of a fake: screen glare, or a device-shaped rectangle around the face. Either one fails the scan immediately.
• Confirm cues are evidence of a real person: 3D-looking landmark geometry, the nose shifting as your head turns, and blinks.

Light mode uses only the deny cues, so it never blocks you for sitting still. Heavy mode also requires at least one confirm cue, such as a blink or a small head movement, which is what defeats most photos.

Where your face data and password live

• No pictures are saved. Camera frames are processed in memory and thrown away; only embeddings are kept.
• Everything is encrypted. Face data and your Mac password are sealed with AES-GCM using a 256-bit key kept in the macOS Keychain.
• Touch ID guards the key. The key needs Touch ID or your password to open, and the unlocked session re-locks itself after the idle period you choose.
• Nothing leaves your Mac. Visage makes no network requests: no cloud, no account, no analytics.
• Several checks before typing. Your password is only typed when the Mac is really at the lock screen, an enabled face matches, liveness passes and Accessibility access is granted.

When you shouldn’t use face unlock

• On a Mac with highly sensitive work data, or where your employer requires stronger authentication.
• In a shared office where someone might realistically hold up a video of you.
• If your Mac is often left unattended in public places.

In those cases, Touch ID or an Apple Watch is the better hands-light option.

The safest settings checklist

1. Turn liveness detection on and set it to Heavy. Settings → Recognition → Liveness.
2. Use Default or More strict match confidence. Less strict is more forgiving, for others too.
3. Pick a shorter auto-lock session. Settings → Password → Auto lock session.
4. Only enable the identities you need. Switch off faces that shouldn’t unlock this Mac.
5. Keep a strong Mac password. Face unlock types it for you, so it can be as long as you like.

FAQ

Can a photo unlock my Mac?

Without liveness checks, possibly. With Heavy liveness, printed photos and photos on a phone screen are rejected with reasonable confidence. A video of you is not reliably rejected.

Does Visage store pictures of my face?

No. Only 512-number face embeddings are stored, encrypted on your Mac.

Where is my Mac password stored?

Encrypted on your Mac with AES-GCM, using a Keychain key that needs Touch ID or your password to open.

Can I delete my face data?

Yes. Delete any enrolled face in Settings → Your Face, or remove your stored password to clear everything; the encrypted files are removed immediately.