Your face stays on your phone.

Both need the front camera to measure facial signals. Frames are analysed in memory one at a time and discarded immediately. Nothing is recorded, saved or transmitted, and the camera is only active while the preview or app is open and on screen.

The face model and all of its code are bundled with the preview and with the app. The first time you launch, your browser downloads that bundle once (about 13 MB) and caches it; after that it makes no network requests while you play.

Settings and any readings you choose to save are stored locally — in your browser's storage for the preview, in the app's private storage on your phone. We have no access to them. Delete them any time from Settings, by clearing site data, or by deleting the app.

If you ask to be notified, we keep your email address so we can tell you when the app is on the App Store. That email goes to the form service we use to hold the list; it is not shared with anyone else and is not used for anything else. Every email we send includes a way to unsubscribe, and you can ask us to delete your address at any time.

This site is static and is served from GitHub Pages. We do not run analytics, advertising or tracking scripts, and we set no cookies. GitHub may keep standard server logs (such as IP addresses) as part of hosting the site; their privacy statement covers that.

Lie Detector App measures visible signs of stress — blink rate, gaze, brow and mouth tension, head and body movement — relative to a baseline it learns from you. It is an entertainment product. It is not a lie detector in any legal, medical or scientific sense, and nothing it shows is evidence about any person. Stress is not deception. Please don't use it to make decisions about anyone.

The app and this site are not directed at children under 13 and collect no personal information from anyone beyond the notification email described above.

If this page changes, the updated version will be published here and the date at the top will move.