.PUB file extension
To open .PUB files on Windows, install and open Microsoft Publisher, then use File > Open to open the .PUB file.
To open a .PUB file, use Microsoft Publisher on Windows. On macOS, Linux, iOS, and Android there is typically no full-fidelity native support, so you’ll usually need to open it on a Windows PC with Publisher (or try an importer that may not preserve layout perfectly).
Last updated: June 10, 2026
Open on your device
Choose your operating system for a dedicated step-by-step opening guide.
How to open .PUB files
Use these platform-specific instructions to open .PUB files safely.
Windows
- 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).
Mac
- If you need accurate layout, transfer the file to a Windows PC and open it in Microsoft Publisher.
- Otherwise, try an application that can import Microsoft Publisher files, understanding that formatting may change.
Linux
- Try opening/importing the .PUB file in an application that supports Microsoft Publisher import (formatting may be incomplete).
- If fidelity matters, open the file on Windows using Microsoft Publisher.
iOS
- iOS typically won’t open .PUB with full fidelity; share or transfer the file to a Windows PC and open it with Microsoft Publisher.
Android
- Android typically won’t open .PUB with full fidelity; transfer the file to a Windows PC and open it with Microsoft Publisher.
Security notes
- .PUB is a complex, proprietary format; treat files from unknown sources as potentially risky because document parsers can have vulnerabilities.
- Prefer opening untrusted .PUB files in a trusted, fully updated viewer/editor (ideally Microsoft Publisher) rather than relying on unknown importers.
- Be cautious with .PUB files received unexpectedly (especially if they prompt you to install software or enable special features); verify the sender and context first.
Can't open this file?
These are the most common causes and fixes when .PUB files fail to open.
Common reasons
- The .PUB file won’t open or shows as an unknown format
- Layout/formatting changes after opening in another app
- A tool identifies the file as application/x-mspublisher but your workflow expects another MIME type
Fix steps
- 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.
Recover a deleted or lost .PUB file
If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.
Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.
Wondershare RecoveritWindows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.
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OS-specific troubleshooting
Convert .PUB to other formats
Use conversion tools to change .PUB files into formats your software supports.
What is a .PUB file?
.PUB is a proprietary publication/document format used by Microsoft Publisher. It is designed for page-layout content (brochures, flyers, newsletters) and may not round-trip cleanly through non-Microsoft tools. In content detection systems, it is commonly identified as application/x-mspublisher.
Background
Microsoft Publisher uses .PUB as its native file format for desktop publishing and page layout. Files often include complex layout elements (positioned text boxes, images, shapes, and fonts) meant to print or export as a final document.
Because the format is proprietary, third-party applications may be able to import .PUB files, but results can vary depending on the Publisher version and the document’s complexity. In practice, the most reliable way to preserve the original layout is to open the file in Microsoft Publisher.
In enterprise and indexing tools, Microsoft Publisher files are recognized as their own document type; for example, Microsoft documentation and Apache Tika identify them with the MIME type application/x-mspublisher. For general web/standards use, you should not assume there is an official IANA-registered media type specifically for Microsoft Publisher.
Common MIME types: application/vnd.exstream-package
Further reading
Authoritative resources for more details on the .PUB format.
- Supported file types in eDiscovery (Microsoft Purview) – includes .pub and application/x-mspublisher
- Apache Tika – Supported Document Formats (includes Microsoft Publisher detection)
- Microsoft Publisher (Wikipedia) – overview of .pub as Publisher’s proprietary format and notes on other apps importing it
- IANA Media Types registry index (to verify official registered media types)
- Shared MIME-info Database specification (freedesktop.org) – how Linux desktop MIME/glob mappings work
- Wikidata: Microsoft Publisher file format, version 3.0 (structured reference for .pub and media type fields)
Common .PUB 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.
FAQ
What program opens .PUB files?
Microsoft Publisher is the primary program for .PUB files. Other applications may import .PUB files, but results can vary and the original layout may not be preserved.
Is there an official MIME type for Microsoft Publisher (.pub)?
In practice, Microsoft documentation and tools like Apache Tika commonly use application/x-mspublisher for .PUB. You should not assume there is an IANA-registered media type specifically for Microsoft Publisher.
Can I open a .PUB file on Mac, iPhone, or Android?
There is typically no full-fidelity native support on those platforms. The most reliable approach is to open it on Windows with Microsoft Publisher, or use a third-party importer with the expectation that formatting may change.
Can I convert a file by renaming it to .PUB?
No. Renaming only changes the extension label. Use the original app’s export/save-as features or a proper conversion workflow.
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