How to open .PGB files on iOS
To open .PGB files on iOS, if the Files app cannot preview it, share the .PGB to a third-party image app that explicitly supports uncommon image formats; otherwise transfer the file to a desktop system for viewing/conversion.
Step-by-step instructions
- If the Files app cannot preview it, share the .PGB to a third-party image app that explicitly supports uncommon image formats; otherwise transfer the file to a desktop system for viewing/conversion.
Common issues
No app can open the .PGB file
Many systems do not include built-in decoders for uncommon vendor-specific image subtypes like image/vnd.globalgraphics.pgb, so the file may be treated as unknown or unsupported.
- On Linux, check the detected MIME type; if it is image/vnd.globalgraphics.pgb, try a different installed image viewer/editor or a conversion workflow that supports that MIME type.
- If mobile devices cannot open it, transfer the file to a desktop OS and try opening/converting it there.
Wrong file association (opens in the wrong program)
The extension may be mapped incorrectly or an application may have claimed the extension without actually supporting the format.
- Change the default “Open with” association to a different image program and retry.
- On Linux, update/rebuild MIME associations (shared-mime-info based) so *.pgb maps correctly to image/vnd.globalgraphics.pgb.
File is detected as .PGB but still fails to render
The file may be corrupted, truncated, or not actually a PGB image despite the extension.
- Re-download or re-copy the file to rule out transfer corruption.
- Verify the file type using a tool that reports MIME type/content signature; if it is not image/vnd.globalgraphics.pgb, treat it according to the detected type instead of the extension.
Security note
.PGB is an image format (image/vnd.globalgraphics.pgb), so it is not meant to contain scripts or macros; the main risk is malformed-file vulnerabilities in image decoders/viewers.