What gets removed?
Camera models, capture dates, GPS coordinates and other fields stored in EXIF, XMP, IPTC or comments are not copied to the output. The browser renders the displayed pixels, then the new file is stripped of metadata blocks. This is a new image export, not a lossless edit of the original compressed file.
Visible faces, addresses, license plates and other identifying content remain in the image. PNG preserves rendered transparency; JPG uses a white background and lossy compression. Color rendering can differ from the original, especially with wide-gamut photos. Animated inputs become a single still frame. Compare the preview and download before sharing.
Verify the downloaded copy
Inspect the downloaded copy with a metadata viewer on your device, for example ExifTool. Basic properties such as pixel dimensions, file format and byte size still exist because they describe the file. Do not expect the file size to decrease: a PNG copy of a JPG photo can be much larger. HEIC must first be converted using the linked tool.