Most photos carry hidden data called metadata. A phone photo usually records the exact GPS position where it was taken, the phone model, the date and time, and the software that edited it. This tool shows you what each photo reveals, with a map link for any location it finds, and then removes it.
For JPG files it deletes the metadata blocks (EXIF, XMP, IPTC, comments and the extra depth or HDR images some phones attach) and copies the compressed picture data byte for byte, so the photo is not re-compressed and loses no quality. PNG files lose their EXIF and text chunks, and WebP files lose their EXIF and XMP chunks, in the same lossless way. Two things are kept unless you untick them: the rotation tag, so phone photos don't turn sideways, and the colour profile, so colours look the same. Neither says anything about you.
Limits: iPhone HEIC photos can't be edited in place in a browser, so they are saved as high-quality JPGs with no metadata at all. TIFF, RAW and video files are not supported. The tool removes data stored in the file; it can't remove what is visible in the picture itself, such as a street sign or a face.