> ## Documentation Index > Fetch the complete documentation index at: https://developers.argosidentity.com/llms.txt > Use this file to discover all available pages before exploring further. # Face Compare API > Compare two facial images to determine their similarity and provide detailed analysis results # Face Compare API The Face Compare API allows users to compare two faces to determine their similarity. With this functionality, users can easily measure the resemblance between two facial images, enabling them to identify and analyze similarities or differences. ## API Overview The Face Compare API provides a powerful tool for facial similarity analysis with the following capabilities: * **Dual Image Comparison**: Compare two facial images side by side * **Similarity Scoring**: Get precise similarity scores between faces * **High Accuracy**: Advanced AI algorithms for reliable comparisons * **Fast Processing**: Quick analysis and response times * **Multiple Formats**: Support for various image formats * **Privacy Focused**: No storage of facial data, only comparison results ## Request Parameters ### Required Parameters * **originFace**: Base64 encoded image of the face to be compared with the targetFace image * **targetFace**: Base64 encoded image of the face to be compared with the originFace image ### Optional Parameters * **callbackUrl**: The URL where the face compare results will be sent upon completion ### Authentication * **x-api-key**: API key essential for authentication and access control purposes ## Response Format The API returns detailed comparison results including: * **apiType**: API type identifier * **transactionId**: Unique identifier for each request * **result**: Object containing the processing result * **face**: Recognition result of the originFace * **targetFace**: Recognition result of the targetFace * **similarity**: Similarity score between the two faces ## Use Cases * **Identity Verification**: Verify if two photos belong to the same person * **Fraud Detection**: Detect identity theft and fake documents * **Access Control**: Verify identity for secure entry systems * **Customer Onboarding**: Ensure consistent identity across registrations * **Document Verification**: Compare ID photos with live captures ## Processing Modes ### Synchronous Processing * Immediate response with comparison results * Best for real-time applications * Direct API response ### Asynchronous Processing * Use callback URL for delayed results * Better for batch processing * Detailed callback response format ## Similarity Scoring The API provides similarity scores that indicate how closely two faces match: * **High Score (80-100%)**: Very likely the same person * **Medium Score (60-79%)**: Possibly the same person * **Low Score (0-59%)**: Likely different people ## OpenAPI ````yaml POST /compare openapi: 3.1.0 info: title: Face Compare API description: API for comparing two facial images and determining their similarity version: 1.0.0 servers: - url: https://idverify-api.argosidentity.com/modules description: Production server security: - apiKeyAuth: [] paths: /compare: post: tags: - Face Compare summary: Compare two facial images description: >- Compare two facial images to determine their similarity and provide detailed analysis results operationId: compareFaces requestBody: required: true content: application/json: schema: type: object required: - originFace - targetFace properties: originFace: type: string description: >- The base64 encoded image of the face to be compared with the targetFace image. * Base64 encoded characters in the payload must not include the MIME type. For example, if the encoded base64 characters are "image/png;base64,/9j/2wBDABQODxIP...", then remove "image/png;base64," and send only the encoded data "/9j/2wBDABQODxIP...". example: >- iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg== targetFace: type: string description: >- The base64 encoded image of the face to be compared with the originFace image. example: >- iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg== callbackUrl: type: string description: >- The URL where the face compare results will be sent upon completion. If a callbackUrl is provided, the process works asynchronously. If no callbackUrl is provided, the process operates synchronously. format: uri example: https://your-domain.com/callback responses: '200': description: Successful face comparison content: application/json: schema: type: object properties: apiType: type: string description: API type identifier example: compare_face transactionId: type: string description: Unique identifier for each request example: txn_123456789 result: type: object description: Object containing the processing result properties: face: type: object description: Recognition result of the originFace properties: isAvailable: type: boolean description: Presence of the recognized originFace example: true boundingBox: type: object description: Bounding Box object for the recognized originFace properties: Width: type: number description: >- Width coordinate of the Bounding Box for originFace example: 0.42534321546554565 Height: type: number description: >- Height coordinate of the Bounding Box for originFace example: 0.567890123456789 Left: type: number description: >- Left coordinate of the Bounding Box for originFace example: 0.12345678901234566 Top: type: number description: >- Top coordinate of the Bounding Box for originFace example: 0.23456789012345677 confidence: type: number description: Confidence score of face detection example: 0.9876543210987654 targetFace: type: object description: Recognition result of the targetFace properties: isAvailable: type: boolean description: Presence of the recognized targetFace example: true boundingBox: type: object description: Bounding Box object for the recognized targetFace properties: Width: type: number description: >- Width coordinate of the Bounding Box for targetFace example: 0.4567890123456789 Height: type: number description: >- Height coordinate of the Bounding Box for targetFace example: 0.543210987654321 Left: type: number description: >- Left coordinate of the Bounding Box for targetFace example: 0.13456789012345677 Top: type: number description: >- Top coordinate of the Bounding Box for targetFace example: 0.2456789012345679 confidence: type: number description: Confidence score of face detection example: 0.9765432109876543 similarity: type: object description: Similarity analysis between the two faces properties: score: type: number description: Similarity score between the two faces (0-1 scale) example: 0.854321098765432 threshold: type: number description: Threshold used for matching example: 0.8 isMatch: type: boolean description: >- Boolean indicating if faces match based on threshold example: true examples: successful-comparison: summary: Successful face comparison with high similarity value: apiType: compare_face transactionId: txn_123456789 result: face: isAvailable: true boundingBox: Width: 0.42534321546554565 Height: 0.567890123456789 Left: 0.12345678901234566 Top: 0.23456789012345677 confidence: 0.9876543210987654 targetFace: isAvailable: true boundingBox: Width: 0.4567890123456789 Height: 0.543210987654321 Left: 0.13456789012345677 Top: 0.2456789012345679 confidence: 0.9765432109876543 similarity: score: 0.854321098765432 threshold: 0.8 isMatch: true low-similarity: summary: Face comparison with low similarity value: apiType: compare_face transactionId: txn_987654321 result: face: isAvailable: true boundingBox: Width: 0.42534321546554565 Height: 0.567890123456789 Left: 0.12345678901234566 Top: 0.23456789012345677 confidence: 0.9876543210987654 targetFace: isAvailable: true boundingBox: Width: 0.4567890123456789 Height: 0.543210987654321 Left: 0.13456789012345677 Top: 0.2456789012345679 confidence: 0.9765432109876543 similarity: score: 0.23456789012345677 threshold: 0.8 isMatch: false '400': description: Bad request - Invalid input parameters content: application/json: schema: type: object properties: error: type: object properties: code: type: string example: INVALID_IMAGE message: type: string example: One or both images are invalid or corrupted '401': description: Unauthorized - Invalid API key content: application/json: schema: type: object properties: error: type: object properties: code: type: string example: INVALID_API_KEY message: type: string example: Invalid or missing API key '500': description: Internal server error content: application/json: schema: type: object properties: error: type: object properties: code: type: string example: INTERNAL_ERROR message: type: string example: An internal server error occurred components: securitySchemes: apiKeyAuth: type: apiKey in: header name: x-api-key ````