Split a PDF by File Size to Beat an Email Limit
Page ranges are the wrong unit when the rejection message says 10 MB. This split works in the units the upload form uses.
What this tool does
Splits a PDF into the smallest number of files that each stay under a size you set, which is what an email or portal limit actually asks for.
How it works
Enter the maximum size per file in kilobytes and download the ZIP. Because pages differ in weight, parts will not be identical in page count — only in staying under the ceiling. Large scanned pages may never fit a very small limit; compress the PDF first, then split.
- Choose the PDF, or drag it onto the page.
- Set file name pattern — the settings below explain what each one changes.
- Run the tool and download the ZIP.
Settings that decide the result
- File name pattern — [BASENAME] is the document name, [CURRENTPAGE] the part's last page (the page it ends on), [PART] the part number and [TOTALPAGES] how many parts there are.
- Max size per file (KB)
- Discard bookmarks
When to reach for it
- An upload or mail server rejects the file. Set the limit it quoted and take the smallest number of parts.
- You want parts as even as possible without going over. The splitter packs pages until the next one would breach the limit.
Questions we get
How does splitting by size work?
Set the maximum KB per part and the tool packs as many pages as fit under it into each PDF — the handiest fix for upload limits on other websites.
Where it fits
The tools people usually open next to Split by size:
- Rotate — Rotate and save PDF pages permanently.
- Delete Pages — Remove pages from a PDF document.
- Split by text — Split when specific text changes from page to page.
Every tool works on a copy, so the original file is never modified. Uploads are stored under an unguessable id and deleted automatically two hours after you last open them; nothing is listed, shared or indexed. More on the security page.