How the face shape is worked out
The detector first finds the face box, then places 68 landmark points on it: along the jawline, along each eyebrow, around the eyes, down the nose and around the mouth. From those points it measures how wide the face is compared with how long it is, and how the width across the brows compares with the width across the jaw.
A face much wider for its length reads as round; one only a little wider with a strong jaw reads as square; a long, narrow face reads as oblong. Within the middle band, a brow line noticeably wider than the jaw points to heart, a jaw wider than the brow points to diamond, and balanced proportions read as oval.
The six shapes in plain words
Real faces rarely fit one box neatly. Treat the label as the nearest match and look at the proportions to see how close you are to the next shape over.
- Oval: longer than wide, with brow and jaw of similar width and a softly rounded chin.
- Round: width and length close to equal, with full cheeks and a soft jaw.
- Square: a broad, angular jaw roughly as wide as the forehead.
- Oblong: noticeably longer than wide, with fairly straight sides.
- Heart: a wider brow and cheekbones narrowing to a smaller chin.
- Diamond: the widest point at the cheekbones or jaw, with a narrower brow.
Photo tips that change the answer
Angle changes measured proportions more than anything else. Tilting the chin up shortens the face in the photo, and tilting it down lengthens it. Turning the head makes one side narrower. Hair over the forehead or jaw hides the outline the landmarks follow, and a wide-angle phone lens held close makes the middle of the face look wider. Stand back, zoom in a little, keep your head level and pull the hair away from your face for the most reliable result.
Using the result
Style advice built on face shapes is a rule of thumb, not a law: it suggests frames, cuts and necklines that balance the proportions the shape describes. Use the result as a starting point and trust what you like in the mirror. The detector says nothing about attractiveness, health or character, and there is no better or worse shape.