I don’t suspect it will purposely compliment you by guessing 10 years younger will it? 

Facial recognition service Face.com has announced a new feature in its API: age detection. After analyzing a photograph of a person’s face, the software returns three values: minimum age, maximum age, and estimated age, along with the confidence level of the guesses. Applications for the new technology include enhanced parental controls and targeted advertising. If you want to test out the service yourself, you can play around with the APIhere (in the photo above, the correct age is ~47).

[Via source]