We built a free AI face shape detector with Claude Vision and Vercel

Epica Beauty built a free AI face shape detector using Claude Vision and Vercel. The tool analyzes a single selfie to classify the user's face shape into one of six categories, returning results with confidence scores and styling suggestions. Photos are processed serverlessly and never stored, with each analysis costing about $0.003.

At Epica Beauty we kept seeing the same question from users: "what face shape do I have?" People were measuring their faces with rulers and comparing themselves to celebrity photos. So we built a small tool that answers it from a single selfie: testmyface.com https://testmyface.com . The stack is deliberately boring. The site is static HTML on Vercel. When a user uploads a photo, a single serverless function sends it to Claude's vision API with a prompt that asks for facial proportions forehead width, cheekbone prominence, jawline shape, length-to-width ratio and a classification into one of six shapes: oval, round, square, heart, diamond, or oblong. The response comes back as JSON with a confidence score and styling suggestions, and the frontend renders it. One page, one function, about $0.003 per analysis. Photos are never written to disk. The image goes from the browser to the function to the API and the result comes back in a few seconds. Things that surprised us: getting the model to commit to one shape instead of hedging between two took more prompt iteration than anything else, and a cheap small model classified faces as reliably as the larger ones once the prompt was strict enough. It is free and has no signup. If you try it, I would love to hear whether the classification matches what you thought your face shape was.