Documentation
README
Find the original image
The goal is almost never "find a match". It is find the earliest publication and read its page. A match tells you the image exists elsewhere; the earliest page tells you the photographer, the date, the caption, and the names โ which is what you actually pivot on.
The beginner mistake: uploading the full frame to one engine, getting nothing, and concluding the image is unindexed. Cropping to one distinctive object and re-searching finds things full-frame search cannot.
Pick your engine by what you are holding
This is the opening of the README. Read the full README on GitHub.