How to split a large PDF into smaller files on a Mac
An upload form or email will not take your PDF. Split it into parts under the limit on a Mac, and when shrinking it is the better fix.
The problem
A portal says files must be under 10 MB and your PDF is 24 MB.
Should I compress or split a PDF that is too big?
Compress first if the form wants a single file, which most do. Split if it is still too large after compressing, or if the form accepts several files. See get a PDF under a size limit.
Where is the size in my PDF?
A scanned page or a page of photos weighs far more than a page of text. In Preview, show thumbnails and look for them. If a few pages are photos, shrinking those usually gets you under. See why a PDF is so big.
How do I split a PDF into smaller files on a Mac?
- Open the PDF in Preview and choose View > Thumbnails.
- Select the first half of the pages: click the first, Shift click the middle one.
- Drag them to the desktop to make part 1.
- Do the same with the rest for part 2.
- Check each part's size in Finder with File > Get Info. If one is still too big, split it again.
How should I name the parts?
Application part 1 of 3, part 2 of 3: the person receiving them knows the order and that nothing is missing.
Our take
Split at natural breaks, not at the halfway page. A part that ends mid statement or mid form makes the receiver open two files to read one section; splitting between documents, even at uneven sizes, keeps each part readable on its own.
In Simply PDF
Simply PDF's Compress shows the new size before you save, and Organise Pages splits into files of any number of pages if it is still too large. Both need a key. See also split a PDF.
Questions
How do I split a PDF to make it smaller than an upload limit?
Split it into parts in Preview by dragging page ranges to the desktop, then check each part's size with Get Info. Compressing first often avoids splitting.
Should I compress or split a PDF that is too big?
Compress first if the form wants a single file. Split if it is still too large, or if the form accepts several files.