Which Face Is Real?
Two portraits. One is a real photograph. One was generated by AI. Can you tell which is which? On WhichOneIsReal, players average about 80% accuracy (last 28 days) — but a 2022 lab study found untrained viewers spot AI faces only 48% of the time [study]. How hard a round actually is depends heavily on which AI model and prompt generated the fake — some are far more obvious than others.
Start the Face Quiz
2 portraits per round — one real photograph, one AI-generated face. Click the real one. After each round you see exactly what gave the AI away. Free, no signup needed.
These two numbers aren't measuring the same thing — the study tested untrained viewers on older StyleGAN faces in a lab setting, while our figure is real accuracy on our current Seedream 4.5 face pool, played by a self-selected, quiz-practised audience. Don't read either as "the" human detection rate — how easy or hard a round is depends heavily on the AI model and prompt behind that specific fake.
Want to learn the tells before you play?
- Eyeglasses, hair edges, skin splotches
- Face boundary blur, lip sync, temporal flickering
- Checklist + famous deepfake examples
Frequently Asked Questions
Which face is real — how do I tell? ▾
The fastest checks: look at the background near the hair — AI often creates a blurry or smeared transition. Check eyeglasses if present — AI glasses are almost always asymmetric. Look for water-like splotches on skin with no shadow. Try to read any text in the background — AI text is always garbled.
Can AI generate realistic faces that fool people? ▾
Yes, and how easy or hard it is depends heavily on the AI model and prompt. A 2022 PNAS study (Nightingale & Farid) found untrained viewers correctly identified older AI-generated StyleGAN faces only 48% of the time — barely better than random guessing. On WhichOneIsReal's own quiz data (currently Seedream 4.5 faces), players currently average about 80% accuracy over the last 28 days. The two numbers test different models and audiences, so neither is a universal 'human detection rate' — some AI faces are far more obvious than others.
What is "This Person Does Not Exist"? ▾
"This Person Does Not Exist" (thispersondoesnotexist.com) generates a new AI face on every page load using StyleGAN — a generative adversarial network developed by NVIDIA. The faces look completely real but are entirely synthetic — no such person exists.
How do deepfakes differ from AI-generated faces? ▾
A deepfake swaps a real person's face onto another body or video. An AI-generated face (StyleGAN, Flux) is entirely synthetic — the person never existed. Both are hard to detect but show different artifacts. → Full deepfake detection guide
How can I get better at spotting fake faces? ▾
Deliberate practice with immediate feedback is the fastest way. Play the face quiz repeatedly — each round you see the correct answer and the key artifact. Research suggests even short training sessions significantly improve accuracy.
More AI Detection Quizzes
Each category trains different detection skills.
