Face Shape Haircut AI is a web-based tool that analyzes a user's face shape from a selfie and generates AI previews of hairstyles matched to that shape. The primary function is to help individuals see how different haircuts would look on their own photo before visiting a barber or stylist. The tool measures the face by mapping 478 points and calculating four ratios: face length to width, forehead width, jaw width, and jaw angle. These measurements are compared against seven face shapes (oval, oblong, round, square, heart, diamond, and triangle) and the result is displayed to the user at no cost. The app does not require a separate download or sign-up; it operates entirely through a phone camera and web browser. Key features include a free face shape report with numerical measurements, the ability to see up to 12 haircut previews rendered on the user's own photo (depending on the paid plan), and a barber card for each cut. The barber card is a one-page PDF that breaks down the cut into specific instructions: length on top, clipper guard numbers and fade height on the sides, back details, texture, styling tips, and recommended trim intervals. The tool preserves the user's natural hair color and hairline and does not add hair where the scalp is visible. Users can compare up to four cuts side by side with their current photo. The app also offers a "Name any cut" feature that allows users to request a specific hairstyle and see it rendered on their photo, with a limited number of tries per plan. Typical use cases involve someone preparing for a haircut appointment who wants to preview options that suit their face shape, hair type, and hairline. The workflow begins with taking a selfie under specific conditions: facing the camera at eye level, in even light, with hair off the forehead and no obstructions like hats or headphones. The tool checks the photo quality in real time and prompts a retake if needed. After the face is measured, the user sees their shape and three blurred previews for free; paying a one-time fee (ranging from $9.99 to $29.99) unlocks full results without a subscription. Paid results are stored for one year, while unpaid photos are deleted after 30 days. The app states that user photos are not used to train AI models and are not shared. Technical details include the use of 478 facial landmark points for measurement and AI rendering that keeps the user's existing hair color and hairline. The tool is designed to work on any device with a camera and good lighting. The barber cards provide precise measurements in inches and clipper guard numbers rather than vague terms like "just a trim." The app also notes that if a user's face shape falls between two categories, it will indicate that (e.g., "Oval, leaning Oblong"). The results are presented as AI previews, and the actual outcome depends on the user's hair and barber skill, which is why each cut includes a detailed barber card.