Split PDF by File Size — Fit Upload Limits
Split a large PDF into several files, each under a size limit you set in MB — for example 8 MB per file for email.
When a file is too big to attach to an email or upload to an online portal, split it into several parts. Set the maximum size per file and the tool divides the pages for you automatically.
How to split a PDF by size (3 steps)
- Open the large PDF.
- Set the maximum size per file (e.g. 8 MB).
- Split the file and get all the parts in one ZIP.
When to use it
- Email attachments — most email providers limit total attachments to around 20–25 MB per message, and scans of a few dozen pages often exceed that.
- Online submission portals — many accept only 2–10 MB per file.
- Sending through chat apps — smaller pieces are easier to send and open on a phone.
How it works
Enter the maximum size per file in MB (the default is 8 MB). The tool estimates from the average size per page, groups pages in order, then checks the real size of each group. Any group that is still too large is halved again until it fits. You get files named part-1.pdf, part-2.pdf, and so on, in a ZIP. If the whole file is already under the limit, you get a single file.
Page content is not compressed or reduced in quality, and text stays searchable.
Limitations to know
- Pages are never cut in half. If a single page is larger than your limit (a high-resolution photo, for example), the part containing it will still be over. Use Compress PDF first.
- To split at page numbers you choose yourself, use Split PDF instead.
Tip
Set the number slightly below the real limit — if a portal accepts 10 MB, enter 9. Some systems measure size a little differently, and email makes attachments larger while sending.
FAQ
My email only allows 25 MB attachments. What should I set?
Set the maximum to 20–24 MB and the file will be split into parts that fit.
Does each part open normally?
Yes. Every part is a complete PDF that opens on its own.
Are pages cut in half?
No. Splits always happen at page boundaries.
Is the page order correct in each file?
Yes. Pages follow the original order: part-1 holds the first range, part-2 the next, and so on, with no pages missing.
Why are some parts much smaller than the limit?
Pages are never cut, and pages vary in size. The last part is often smaller because it holds the remaining pages.
Can I join the parts back into one file?
Yes. Use Merge PDF and put them in order — part-1, part-2, and so on — to get the complete original back.