How to spot a live deepfake on a video call

Informational only. No test is perfect. If someone pressures you for money, photos, or secrecy during a suspicious call, treat it as a scam until you verify them another way (in person, or a number you already trust).

Why this matters now

Deepfake tools can alter how someone looks or sounds on a live video call, not only in pre-recorded clips. Fraud rings use that to seem trustworthy, impersonate a boss or relative, or run romance and investment scams. Parents and teens should know simple, low-tech ways to stress-test whether the video is real.

What is the three-finger test?

The three-finger test means you ask the person on the call to hold three fingers up directly in front of their face. That creates occlusion: the hand blocks part of the face. It also forces quick changes in how light falls on the scene and in spatial depth (hand closer than the face).

For a real person, that movement is usually natural. Many real-time deepfake pipelines still struggle when face and hands must line up believably under occlusion. You may see fingers that merge, warp, or lose sharp edges, or the face overlay may slip or jitter around the hand. Those artefacts can appear in seconds.

Coverage of a scammer failing this check on a call, and why the gesture is hard for some fakes to handle, is summarised in press reporting such as IBTimes UK (March 2026).

Other signs on a live call

• Unnatural delay or lip sync: voice and mouth movement slightly out of step.
• Weird edges or blur: around hair, jawline, or when they turn their head quickly.
• Refusal to follow simple live requests: besides three fingers, you can ask them to turn side-on, wave slowly, or hold an object you name. A real person can usually comply; a rigid refusal plus urgency is a red flag.
• Pressure for money or sensitive info: deepfake or not, that pattern is the core scam signal.

Limits parents should know

The three-finger test is not infallible. Better models may eventually handle occlusion and hands more convincingly. Use it as one layer of defence, not a guarantee. The safest habit is: verify high-stakes requests through a second channel you already trust, and never send money or intimate images because a video call “looked” like someone you know.

Related: AI-generated and synthetic content · Live streaming and video chat