Provides every engine imaginable.

A must have add-on if you use reverse image search even occasionally. This is truly a cool feature. It is saves my time mostly.

A must have add-on if you use reverse image search even occasionally. Moved recently from "Image Search Options" by Xamayon

Nothing not to love - does exactly what it says it does. While the image search platforms themselves may not always yield the results you want, Search by Image is a handy shortcut to have, and much faster than going to those sites manually. For me, it was something I didn't think I'd need until I needed it.

Many people have already mentioned how great the reverse image search is, but I want to point out that this extension also has a very powerful "OPEN IMAGE" option. Open Image, lets one see and save images that don't have IMG URLs.

For example, sites like artsandculture.google.com will send very high resolution images as tiled PNGs and use JavaScript to stitch them together. Each tile is just a data blob so all the other extensions I tried (Download All Images, Save Images, etc) failed to even detect that the image exists, much less let me save it.

I don't know how Search by Image is able to find images that other extensions miss, but I hope that eventually the author (Armin Sebastian @dessant) will create an extension that can download all such images from a page in a single click.