Upload forms and email gateways count kilobytes, not pages. Split by size packs as many pages as possible under a ceiling, which is more reliable than guessing how many pages will fit.
Step by step
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1
Upload your PDF
Drag your PDF onto the box or click Choose file. It is sent over an encrypted connection and only used for this task.
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2
Set the options
Adjust max size per file (kb), file name pattern and discard bookmarks. Every field has a sensible default, so you can usually run the tool straight away.
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3
Pick a size limit
Set the maximum size per file. The splitter packs as many pages into each part as will fit, so you get the fewest possible files.
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4
Run it and download
Press Split by size and the page shows progress while it works. When it finishes you get a download link — nothing is emailed and nothing is stored longer than it needs to be.
The limit is a ceiling, not a target
Enter the maximum KB per part. The splitter packs pages until the next page would break the limit, then starts a new part. That gives you the smallest number of files rather than a neat equal division. Leave a little headroom below the site’s stated limit; attachment encoding can add a few percent.
Large pages and scans
One full-page scan can be larger than a whole text document. If a single page exceeds the ceiling, the split cannot make that page smaller. Compress the PDF first or reduce the scan resolution, then split the lighter copy.
Check every part
Look at the file sizes in the ZIP and confirm each is below the limit. Open the first and last part and check the page order. Name the parts with the source basename and part number so a later upload does not mix them with another job. Keep the original until the upload succeeds.
Good habits for Split by size
- Page thumbnails are tap-friendly, so you can reorder and delete on a phone.
- Every tool works on a copy — your original file is never modified.
- Use Split by text when a document has no bookmarks to split on.
Common questions
Is this tool free?
Yes. Every tool on this site is free to use, with no sign-up, no watermark and no daily task limit.
Do I need to install anything?
No. The tools run in your browser and are processed by this server.
What happens to my files?
They are stored under an unguessable id and swept automatically after a couple of hours. Nothing is shared or indexed.
Does it work on a phone?
Yes. The page pickers and editors are built for touch, so dragging, rotating and selecting pages all work without a mouse.
What does Split by size do exactly?
Set the maximum size per file — we split the pages into as few parts as possible.
Why is one part still over the limit?
A single page can be larger than the requested ceiling. Compress the PDF or reduce oversized images before splitting.
Does splitting by size reduce quality?
No. It copies pages into separate documents; it does not recompress the images. Compression is a separate step.
Can I split by size and hit an exact file size?
The tool aims for the smallest number of parts under the ceiling, not an exact target. Leave headroom for email or form overhead.