Reverse image search finds copies of your content across the web by analysing the visual characteristics of an image rather than searching for text. Tools like Google Lens, TinEye, and Yandex compare an image's visual features against very large indexes of images to find matches.
For creators, reverse image search is one of the best ways to find leaked content that isn't labelled with your name, for example a thumbnail or screenshot reposted without any identifying text. It can often match images that have been resized, lightly cropped, or recompressed, although heavy edits can defeat it.
Privly uses reverse image search as part of its scanning, alongside username search and content fingerprinting. When copies of your content are found, Privly can file DMCA takedowns with the site and its host and request removal from Google search results.