Safety and honest limits

Halo is a hint, not proof. Here is what it gets wrong, what it does about it, and what to do when you’re not sure.

The six limits

1. A hint, not proof. It can name the wrong person, especially relatives, look-alikes and children. Never use it to decide who to trust or let in.
2. Silence doesn’t mean a stranger. Dim light, side angles, masks, new glasses or a haircut can stop a match.
3. It works better for some faces than others. Open face models make more mistakes for darker-skinned and East Asian faces, women, children and older people.
4. It only knows people who said yes. It can’t look anyone up. Each face in view is measured for a moment, checked against your list, then forgotten.
5. The app records that you asked them, but it can’t check. Remove anyone the moment they ask.
6. A prototype, tested so far mainly on AI-generated faces, not yet with people who have face blindness. Without earbuds, your phone speaks out loud.

How Halo tries not to be wrong

• Three states. It speaks only when it’s sure: one face, steady for at least a second and five frames, one of them facing the camera, clearly closer to one person than to anyone else. Otherwise it shows “Could be Raj?” and stays quiet, or “No match”.
• Children and look-alikes are held at “Could be”; it warns you when you add someone who looks like a person already on your list.
• Careful is the default. Balanced speaks a little more readily, and is wrong a little more often.
• Event mode compares faces with today’s list only, so there are fewer people to mix up.

When you’re not sure

• Look for the cue it shows: clothes, hair, glasses, a voice.
• Let them speak first; voices help many people with face blindness.
• It’s fine to ask: “Remind me where we met?” Most people are kind about it.
• Tap the caption to hear the line again, or open “Who was that?” for the last five.

When it names the wrong person

• Tap Wrong person? under the caption. Halo notes the report on your phone (nothing is sent) and, in Settings, suggests what would help: the Careful setting, more photos of that person, or holding them at “Could be”.
• Add new photos when someone’s look changes: a haircut, new glasses, a beard.
• If two relatives keep being mixed up, add cue notes that tell them apart and turn on “Never whisper” for one of them if you’d rather check yourself.

If you feel unsafe

Halo can’t tell you whether someone is safe. If you feel unsafe, move somewhere public and contact someone you trust or your local emergency number.