This online service finds similar photos on your computer (Windows, Mac OS and Linux). It is free and without registration: simply click and start the search.
One image searches inside a folder for similar pictures to a given source image.
All similarities finds multiple groups of similar images in a folder (example of such image clustering).
Near duplicates will be found, that is exact or resized pictures, images with small color changes, minor watermarks. It will not find strongly cropped or rotated images, similar objects, or same objects taken from different views, lighting conditions etc.
JPG, PNG, BMP, WEBP, GIF (static and animated) of maximum size 40MB per image. Transparency is ignored in image comparison.
Read about this photo comparison algorithm and check out image similarity in Go (Github) for your company or project. The open-source Golang code implements the image comparison function. The code does not include the duplicate image finder (clustering algorithm).
Parameters are set to find reasonably high number of near-similar images with acceptable speed and low false positives. The idea is to offer ready-to-use solution for majority of typical cases without many customizable parameters.
Images are compared by perceptual similarity in terms of color and brightness across the whole image. Partial occlusions, e.g. watermarks, impact perceptual similarity. If the perceptual changes are small, the pictures are considered similar. Rotated and mirrored images are considered distinct.