Face++ - API for face detection – also detects gender, age, pose
Icons8 Background Remover - Quickly remove the background from any photo
Facesoft - The world's most accurate face recognition algorithm
remove.bg - Remove the background of any image 100% automatically
Facial Recognition by FB - Get notified if someone tries to use your photo on Facebook
ClippingMagic.com - Remove image backgrounds online. Make backgrounds transparent, white, etc. Edit, crop, rotate, fix colors, add shadows, all you need for great photos!