My .pub file is 200 MB. Why, and what do I do?
A four-page newsletter shouldn't weigh as much as a film. But open the folder of old parish bulletins or school yearbooks and you will find .pub files of 100 MB, 200 MB, sometimes more. They open slowly, they won't go by email, and some converters refuse them.
The size almost always comes from pictures. Here is how that happens, and what to do with a big file now.
Where the megabytes come from
Photos at full camera size are the main cause. When you insert a picture into Publisher, it is usually stored inside the .pub file at the size it came off the camera or phone. A modern phone photo is several megabytes and far larger than a printed newsletter needs. Put thirty of them on four pages and the file grows to match, even if each one is printed the size of a stamp. Cropping a photo in Publisher hides part of it, but the hidden part usually stays in the file.
The same picture pasted many times adds up too. A logo on every page, a decorative border built from one image copied around the page, a photo pasted into each month of a calendar. Depending on how it was inserted, Publisher can store each of those as its own copy.
Linked pictures are the opposite case. A linked picture stays in its own file next to the .pub, and the .pub points to it. That keeps the .pub small. If you are copying a project that uses linked pictures, copy the picture files with it.
What happens when you convert a large file here
Large uploads go up in 50 MB pieces. If one piece fails because the connection drops for a moment, that piece is tried again, up to three times, so one bad second doesn't cost you the whole upload. Keep the page open until the upload finishes.
A paid job takes up to 20 files and 2 GB. A 200 MB file fits easily.
The free preview is a different matter, and we'd rather be clear about it. The preview takes files up to 25 MB and 100 pages. A 200 MB file is too big to preview. If you want to see how your files come out before you buy, preview a smaller file from the same set, one made by the same person in the same version of Publisher. It will tell you a lot about the rest. And if the full conversion disappoints you, refunds are available within 7 days at [email protected].
What the converted files look like
In a PDF, your pictures are kept as they are. The exception is very large images, over 64 megapixels. Those are scaled down. A picture that size is far beyond what any printed page needs, so you won't see the difference on paper. Because pictures are otherwise kept, a PDF from a 200 MB .pub can also be large.
In a Word file, a picture that appears many times is stored once. A logo on every page no longer means a copy for every page, so the Word file stays much smaller than it would otherwise be.
If you have a whole archive of large files, the PubConvert app for Windows converts on your own PC. Nothing is uploaded, and it doesn't have the website's 20-file and 2 GB job caps. It is a separate one-time purchase from the Microsoft Store.
Making the files smaller
Publisher has a Compress Pictures command. It reduces stored photos to a sensible size for print or for screen and removes the cropped-away parts. People who still have an installed copy of Publisher, such as Office 2021, can open a large file, compress the pictures, and save it under a new name. Keep the original as well.
Microsoft 365 subscribers no longer have that option. Publisher left Microsoft 365 on 1 October 2026, so the file can't be fixed at the source any more. In that case, convert the file as it is, then work with the result. In Word, you can select a picture and use Compress Pictures there. Many PDF tools can also reduce a PDF's size when you save a copy for email.
A few steps that work for any large file:
- Check the free space on your computer before you start. You need room for the original and for each converted file.
- Use a wired connection or stay close to the Wi-Fi router for the upload.
- Convert the big files on their own, in a job of one or two files, so a slow upload doesn't hold up the rest of the batch.
- Keep the original .pub after converting. It is your full-quality copy.
Preview a smaller file free to see how your set comes out.