Native macOS app · macOS 14+

Face-recognition security for your Mac.

Mona Lisa is a lightweight menu-bar agent that checks who is sitting at your Mac. If it can't verify an enrolled face, it locks every screen and records whoever's there — until your password is entered (or a trusted face is). The lock survives a reboot.

Download for Mac How it works
  • Runs fully on-device
  • On-device face model
  • ~0% CPU when idle

Install in about a minute

Requires macOS 14 Sonoma or later and a camera. Apple Silicon & Intel.

  1. Download & drag

    Grab MonaLisa.dmg, open it, and drag Mona Lisa onto the Applications shortcut.

  2. Get past Gatekeeper (one time)

    This build isn't notarized, so macOS blocks the first launch. Open System Settings → Privacy & Security, scroll to “Mona Lisa” was blocked, and click Open Anyway. Or clear the flag in Terminal:

    xattr -d com.apple.quarantine "/Applications/Mona Lisa.app"

  3. Enroll, set a password, go

    Click the shield in the menu bar: Add a Person to enroll your face (grant camera access when asked), set an unlock password in Settings, then hit Start Monitoring. Done — it auto-starts at login from now on.

How it works

Three moving parts, all native macOS. No accounts, no cloud, no agents phoning home.

1

Enroll the faces you trust

A live preview guides you through five head positions — front, both sides, up, and down — capturing 15 samples so the face is recognized from every angle, and auto-calibrates a match threshold. Add as many people as you like and remove them any time.

2

It watches from the menu bar

Every 30 seconds (you choose), it wakes the camera for a single frame, runs Apple's Vision framework on-device, and goes back to sleep. The camera light just blinks — and between checks the app sits at ~0% CPU.

3

Strangers get locked out — on camera

The moment it's sure an unrecognized person is using the Mac, it drops a full-screen lock over every display and records video of the whole locked period. It disables force-quit and app switching, re-applies itself after a reboot, and unlocks with your password — or a trusted face passing a blink check.

Features

  • Intruder video — records the entire locked period
  • Multiple trusted people — enroll anyone by name
  • Survives a reboot — restarting won't unlock it
  • Separate password — PBKDF2-hashed, never stored in plaintext
  • Fully tunable — interval, strictness, camera choice
  • Activity log — every sighting and lock, timestamped

A deterrent against opportunistic use, not full-disk encryption — pair it with FileVault for real theft protection.

Versions

The download button always fetches the latest version.

v0.3.0

More accurate recognition

  • Face alignment — each face is leveled and scaled to a consistent crop before matching, so lighting and head tilt matter far less
  • Quality gating — frames too far or too dark are skipped instead of guessed, with live coaching during enrollment
  • Corroborated matching — two enrolled samples must agree, so a fluke frame can't authorize the wrong person
Past release
v0.4.1

Real face recognition

  • On-device SFace Core ML model — reliably tells people apart, with precise 5-point alignment
  • Fail-secure presence lock: a clearly-unrecognized person is locked out in about a second
  • Records video of the whole locked period, not a photo
  • Face unlock with a blink liveness check — a photo can't unlock; password always works
Past release
v0.4.2

Automatic updates

  • Checks for a newer version on launch and once a day, and guides you to update when one is available — so everyone stays on the latest build
  • On-device SFace recognition, fail-secure presence lock, and video capture of the locked period
Past release
v0.4.3 Latest

Can't be switched off

  • Pausing or quitting now requires your unlock password — or a blink — the same check as the lock screen, so an unauthorized person can't just turn protection off
  • Builds on 0.4.2: automatic update checks, on-device SFace recognition, and video capture of the locked period
MonaLisa.dmg · 36 MB

Download Mona Lisa

Download for Mac

Native macOS app · macOS 14+