A photograph can carry information that is not visible in the picture, such as camera details, comments or location tags. Reencoding a decoded image avoids copying that original metadata into the prepared output.
Image Metadata Remover performs that pixel reencoding. It is not a forensic inspection tool that lists and individually edits every original tag.
Know what is removed and what remains
Original EXIF, embedded comments and colour profiles are not copied. Supported EXIF orientation is applied to the pixels before the new file is written when the host can read it.
Visible information remains. A house number, face, document name or watermark printed in the picture is still part of the pixels. Metadata removal does not remove that content.
The chosen format determines whether alpha survives and how the file is encoded. PNG can retain transparency; JPEG needs a solid background and introduces its own lossy quality decision.
Colour profiles deserve attention
Removing a profile can change colour appearance in a colour managed workflow. Keep the original for archival or print work where those details matter.
A smaller or larger output byte count does not by itself prove which original tags existed. The tool's behaviour is based on writing fresh pixels, not on presenting a complete before and after metadata inventory.
The plugin does not save a permanent copy of the upload in the Media Library, but the WordPress server still processes the file. Hosting logs, backups and other software are outside its control.
Inspect the downloaded image visually and, for a sensitive workflow, verify the resulting file with a suitable metadata inspection process. Fresh encoding is a useful preparation step, not a universal guarantee that sharing the visible image is private or appropriate.
Reference: PHP image decoding documentation.