Building a Face Recognition Login System for Web Apps
Developer tutorial: build a face recognition login system using a REST API — registration, authentication, and liveness verification for web applications.
Concept
Replace passwords with face recognition. Users register their face once, then log in by looking at their camera. The API handles all the AI — you build the UI and auth logic.
Registration Flow
async function registerFace(userId, imageFile) {
const formData = new FormData();
formData.append("face_image", imageFile);
const response = await fetch(
"https://faceapi.arsa.technology/api/v1/face_recognition/register_face",
{
method: "POST",
headers: { "x-key-secret": API_KEY, "x-face-uid": userId },
body: formData
}
);
return response.json();
}
Login Flow
async function loginWithFace(imageFile) {
const formData = new FormData();
formData.append("face_image", imageFile);
const response = await fetch(
"https://faceapi.arsa.technology/api/v1/face_recognition/recognize_face",
{
method: "POST",
headers: { "x-key-secret": API_KEY },
body: formData
}
);
const result = await response.json();
if (result.faces && result.faces.length > 0) {
const face = result.faces[0];
const userId = face.recognition_uidresult;
const confidence = face.recognition_confidence;
const isReal = face.passive_liveness.is_real_face;
if (userId !== "unknown" && confidence > 0.8 && isReal) {
// Authentication successful
return { success: true, userId };
}
}
return { success: false };
}
Webcam Capture
async function captureFromWebcam() {
const stream = await navigator.mediaDevices.getUserMedia({ video: true });
const video = document.createElement("video");
video.srcObject = stream;
await video.play();
const canvas = document.createElement("canvas");
canvas.width = 640;
canvas.height = 480;
canvas.getContext("2d").drawImage(video, 0, 0);
stream.getTracks().forEach(t => t.stop());
return new Promise(resolve => {
canvas.toBlob(resolve, "image/jpeg", 0.8);
});
}
Security Considerations
is_real_face) to prevent photo attacksFor understanding 1:N recognition vs 1:1 verification, read our technical explainer.
Get your API key and start building.