CloudSight - Image recognition API; send an HTTP request with an image, get a description of contents.
API List - A collective list of APIs. Build something.
Google Vision AI - Cloud Vision API provides a comprehensive set of capabilities including object detection, ocr, explicit content, face, logo, and landmark detection.
Abstract APIs - Simple, powerful APIs for everyday dev tasks
Flico - Add visual search to your Chrome browser
Phantombuster - A marketplace of simple to use no-code APIs