TinEye is a web-based reverse image search engine that uses sophisticated computer vision and image recognition technology to help users find out where an image appears online and whether it has been modified or edited. It can be used to identify people in a photo, find out if an image has been used elsewhere online, or to track down the original source of a photo. TinEye can be used to uncover plagiarism, detect copyright violations, protect intellectual property, and spot manipulated images, such as those used in scams and phishing attempts. TinEye is free to use but also offers paid plans with additional features, such as the ability to search for images within specific domains.
I found the sauce when TinEye did not.