How to open .PUB files on Windows
To open .PUB files on Windows, install and open Microsoft Publisher, then use File > Open to open the .PUB file.
Step-by-step instructions
- Install and open Microsoft Publisher, then use File > Open to open the .PUB file.
- If you don’t have Publisher, try opening/importing the .PUB file in an app that supports Publisher import (results may vary).
Common issues
The .PUB file won’t open or shows as an unknown format
This usually happens when Microsoft Publisher (or a compatible importer) isn’t installed on the device, or the OS has no associated app for .PUB.
- On Windows, install Microsoft Publisher and open the file from within Publisher (File > Open).
- On non-Windows devices, move the file to a Windows PC with Publisher for the most reliable results.
Layout/formatting changes after opening in another app
Because .PUB is proprietary, importers may not fully support all layout features, fonts, or embedded objects.
- Open the file in Microsoft Publisher to preserve layout and typography as authored.
- If you must use an importer, compare the output carefully (especially text reflow, image placement, and missing fonts).
A tool identifies the file as application/x-mspublisher but your workflow expects another MIME type
Some systems detect .PUB as application/x-mspublisher; assuming an IANA-registered type may cause handling issues in strict pipelines.
- If you control the pipeline, allow application/x-mspublisher for Publisher content where appropriate.
- If you need broader compatibility, open in Publisher and export to a more widely supported format used by your workflow.
Security note
.PUB is a complex, proprietary format; treat files from unknown sources as potentially risky because document parsers can have vulnerabilities.