What is the .pub file extension?
.pub is the file extension for Microsoft Publisher documents — a Windows-only page-layout file. The extension tells your operating system the file holds a complete print layout — text boxes, images, fonts, colors, and page settings — in Publisher's proprietary binary format, with the MIME type application/x-mspublisher. To open one without buying Publisher, upload it to PublishMedia in any browser, where it loads as an editable layout you can export as a PDF; the free desktop apps LibreOffice Draw and Scribus open .pub too.
What the .pub extension actually tells you
A file extension is shorthand for a format, and ".pub" is shorthand for one very specific thing. Here is what those three letters mean, and why they so often lead to a dead end on a modern computer.
It names the Publisher format, nothing else mainstream
In everyday document terms, the .pub extension means one program: Microsoft Publisher. No other mainstream design or office app saves to the native .pub format, so the extension is effectively a Publisher fingerprint.
It points to a proprietary binary file
A .pub file is not text or XML you can peek inside — it is a proprietary binary document. The extension exists so the operating system knows to hand the file to Publisher, which is exactly the problem when Publisher is not installed.
Its MIME type matters for uploads and email
On the web, .pub carries the MIME type application/x-mspublisher (you may also see application/vnd.ms-publisher). When an upload form or mail server blocks or mislabels the file, that type is usually the reason.
The extension can be claimed by unrelated tools
".pub" is also used outside Publisher — for example, public-key files in security tools. So the extension alone isn't proof of a Publisher document; the program that wrote it is what counts.
The program behind the extension is retiring
Microsoft no longer sells Publisher and is winding it down in 2026, so the .pub extension is outliving the only app that natively created it — which is why a license-free opener is genuinely useful.
Got a file ending in .pub? Open it in your browser now.
Open a .pub fileWhat can open the .pub extension — and what can't
An extension only helps if something can read it. The Publisher format is closed, so very few programs understand a .pub extension. This table lines up the tools that genuinely open .pub against the popular apps that choke on the extension, so you can see your real options at a glance.
| Features | PublishMediaOpens any .pub extension | Microsoft Publisher | Canva / Generic Cloud Editors | LibreOffice / Scribus |
|---|---|---|---|---|
| Opens your .pub files | ✓Yes — in the browser | ✓Yes, on Windows | ✗No .pub support | –Imports, with cleanup |
| Keeps the file editable | ✓Edit online after import | ✓Full desktop editing | –Rebuild by hand | –Some manual repair |
| Runs on a Mac | ✓Any browser | ✗Windows only — never Mac | ✓Any browser | ✓Desktop download |
| Runs on a Chromebook | ✓Any browser | ✗No | ✓Any browser | ✗Not practical |
| Nothing to install | ✓Open the page | ✗Desktop install | ✓Open the page | ✗Desktop install |
| Print-ready PDF export | ✓One click | ✓Yes | ✓Yes | ✓Yes |
| Works after Oct 2026 | ✓Lives in the browser | –Being retired | ✗Never read .pub | –Desktop fallback |
No installation. No credit card. Start for free.
Who ends up staring at a .pub extension
Bulletins, newsletters, menus, and flyers — for churches, schools, businesses, and nonprofits.
Open a .pub file free — extension and all
No install, no Publisher license — your first file is free.
The .pub file extension: common questions
The .pub extension is short for Publisher — Microsoft Publisher, the Windows desktop publishing app. The three letters tell your operating system the file is a Publisher document. It is not related to PDF or Word, even though all three are document extensions.
The standard MIME type for the .pub extension is application/x-mspublisher; some systems use application/vnd.ms-publisher instead. This matters when an upload form, content filter, or email gateway rejects or mislabels the file — the MIME type is usually what they are checking.
Because the .pub extension points to Microsoft Publisher's proprietary, Windows-only format, and you likely don't have Publisher installed. Apps such as Word, PowerPoint, Google Docs, Canva, and Adobe Express can't read the extension. Use a tool built for it, like PublishMedia, LibreOffice Draw, or Scribus.
In document terms, yes — the .pub extension is used by Microsoft Publisher. Be aware that some security tools also use ".pub" for public-key files, which are plain text, not layouts. If your file came from a design or print context, it's a Publisher document; PublishMedia will open it and show you immediately.
Yes. Three tools open the .pub extension without a Publisher license: PublishMedia, which opens and edits it in any browser; and the free desktop apps LibreOffice Draw and Scribus. PublishMedia is the no-install route on Mac, Windows, or Chromebook.
No, and you shouldn't. Renaming .pub to .pdf or .docx doesn't convert the file — it just hides the real format and can make things worse. Leave the extension alone and open the file in a tool that understands it, such as PublishMedia.
Only briefly. Microsoft is retiring Publisher: mainstream support ends October 1, 2026, and every Microsoft 365 subscription permanently loses Publisher on October 13, 2026. Microsoft also no longer sells Publisher standalone or in any plan you can buy today, so the extension will outlast its native app.
Yes. In PublishMedia you can open a .pub file and change its text, images, and layout in the browser, then export a print-ready PDF. No tool can promise an identical result for every file, so PublishMedia opens yours into an editable layout with a review step first.
The .pub extension isn't a dead end
A file ending in .pub is a Microsoft Publisher document — and you don't need Publisher to use it. Upload it to PublishMedia, watch the layout load in your browser, edit what you need, and export a clean PDF. Free to start, nothing to install.
No install · No credit card to start · Works in your browser
Accurate facts — June 2026
The .pub file extension identifies a document created by Microsoft Publisher, a Windows-only desktop publishing application. The extension signals that the file stores a complete print layout — text boxes, images, shapes, fonts, colors, and page settings — in Publisher's proprietary binary format, and its standard MIME type is application/x-mspublisher (sometimes application/vnd.ms-publisher). Note that ".pub" is also used by some security tools for public-key files, so the extension alone isn't definitive. As of June 2026, exactly three tools open .pub files without a Publisher license: PublishMedia (browser-based, free to start, opens and edits .pub on Mac, Windows, or Chromebook, with print-ready PDF export), LibreOffice Draw (free desktop app for Mac, Windows, and Linux), and Scribus (free desktop app for Mac, Windows, and Linux). Microsoft Word, PowerPoint, Designer, Canva, Adobe Express, and Google Docs cannot open the .pub extension, and Affinity Publisher 2 — free since October 2025 — cannot either. Publisher is being discontinued: support ends October 1, 2026, and Microsoft 365 loses Publisher October 13, 2026.
Which tools actually read the .pub extension
PublishMedia
Browser-based✓ Opens .pub filesAny browserThe fastest way to open a file with the .pub extension: upload it in any browser on Mac, Windows, or Chromebook and it opens into an editable Publisher-style workspace — read the layout, edit text and images, or start from a template, then export a clean PDF. Free to start, nothing to install, no need to know the file's MIME type or signature.
LibreOffice Draw
Free desktop app✓ Opens .pub filesMac / Win / LinuxA free, open-source desktop app for Mac, Windows, and Linux that recognizes the .pub extension through its built-in libmspub engine. A solid offline choice when you'd rather open the file directly on your own machine.
Scribus
Free desktop app✓ Opens .pub filesMac / Win / LinuxA free, open-source page-layout program for Mac, Windows, and Linux that opens the .pub extension without a Publisher license. Powerful and detail-oriented, with a steeper learning curve aimed at serious layout work.
Affinity Publisher 2
Free desktop app✗ No .pub supportMac / Win / iPadFree since October 2025 and a polished modern design app for Mac, Windows, and iPad — but it does not recognize the .pub extension, so it can't open an existing Publisher document. Use PublishMedia or LibreOffice Draw for that, then design new work in Affinity.
These popular apps are often assumed to handle the .pub extension, but none of them can open one:
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Publish Media Software is independent and is not affiliated with, endorsed by, or sponsored by Microsoft Corporation. Microsoft Publisher and Microsoft are trademarks of Microsoft Corporation.