Does re-encoding change how the picture looks?

It redraws the same pixels, so it looks the same to the eye. A JPEG is saved again at the chosen quality, which costs a little sharpness; choosing PNG or a high quality keeps that to a minimum.

Why does the file sometimes get bigger?

The original may have been compressed very hard or stored as a smaller size. Re-encoding at a high quality can produce more bytes than you started with, and the change line shows that rather than hiding it.

Is the metadata really gone?

Original file metadata is generally not transferred when canvas pixels are encoded into a new file. Verify the downloaded file using a metadata viewer, and remember that text, faces, or locations *visible in the pixels* are not removed.

EXIF Remover

Strip metadata

Image

Output format Quality 90

Re-encoding an image through a canvas rebuilds the pixels and carries nothing else along, so the EXIF block with the camera, the capture time and the GPS position is left behind. The picture is processed on this device.

Learn

EXIF Remover Guide

About this tool

A photo carries more than the picture: the camera model, the time it was taken, the software that saved it and often the exact place on the map. Re-encoding the pixels through a canvas rebuilds the image without any of that, so what you share carries only what you can see.

Questions

Does re-encoding change how the picture looks?: It redraws the same pixels, so it looks the same to the eye. A JPEG is saved again at the chosen quality, which costs a little sharpness; choosing PNG or a high quality keeps that to a minimum.
Why does the file sometimes get bigger?: The original may have been compressed very hard or stored as a smaller size. Re-encoding at a high quality can produce more bytes than you started with, and the change line shows that rather than hiding it.
Is the metadata really gone?: Original file metadata is generally not transferred when canvas pixels are encoded into a new file. Verify the downloaded file using a metadata viewer, and remember that text, faces, or locations visible in the pixels are not removed.