How to remove metadata from a PNG file

The short answer

A PNG almost never carries GPS coordinates, but it can hold text, a software name, a colour profile and sometimes a full EXIF block. Cleaning means re-encoding — which is exactly what AnonShot does on upload.

Why PNG differs from JPEG

JPEG keeps its metadata in a standardised EXIF segment, the one holding the GPS position of phone photos. PNG is built from successive blocks called chunks, and metadata can sit in several of them.

In practice a PNG almost never comes from a camera: it is a screenshot, an export from a drawing app or a chart. The risk is therefore not geolocation but software traceability.

What a PNG can actually contain

The relevant blocks have short names and can be read with any file inspector.

• tEXt and iTXt: free text, often the name and version of the exporting software, sometimes a comment or an author name.
• tIME: the image's last modification date.
• eXIf: a full EXIF block, possible since 2017, which some software adds when converting from a JPEG.
• iCCP: the colour profile, harmless but it inflates the file.

The real risk in a screenshot

For a PNG, what is visible almost always outweighs what is hidden. A screenshot reveals open tabs, a username in the title bar, a notification, a file path, the system clock.

Before sharing a capture, read the whole thing rather than focusing on its metadata. Crop away anything beyond the subject.

Cleaning a PNG

Re-opening the image and re-exporting it from a simple editor is enough to drop most text chunks. On the command line, exiftool -all= works just as well on PNG as on JPEG.

The fastest route, when the image is going to be shared anyway: drop it onto AnonShot, which re-encodes it without the metadata blocks and returns a short link.