Split a PDF by File Size for Email Limits
Gmail’s attachment cap is still 25 MB. Many Indian exam and job portals ask for 1 MB or 2 MB. If the document is a 40-page scan, “extract pages 1–3” is the wrong control — you still need every page, just in pieces the mail server will take. FlashKit’s Split PDF tool now packs pages in order until the next page would exceed 1 MB, 2 MB, 5 MB, or a custom megabyte cap. The work stays in the tab. The file is not uploaded to FlashKit Tools.
Why size, not page count
A 10-page text export can be 80 KB. A single phone-scan leaf can be 4 MB. Splitting “into two halves by page number” can still leave one half over the portal limit if the heavy photos landed in that half. Size mode walks the pages in order, builds a candidate part, and starts a new file when the next page would go over. That is greedy packing, not magic compression.
The older range how-to still covers extracting chapters by page number. Use that when the recipient does not need the whole book. Use size mode when they do, but the pipe will not take the whole byte weight. The decision fork with the compressor is still compress vs split for email size.
Split by 1, 2, or 5 MB
Unlocked PDFs only. A page already over the cap is saved alone and flagged.
Open Split PDFStep-by-step
- Unlock a password PDF in a desktop reader first. This tool rejects encrypted files on purpose and will not ask for a password in the browser.
- Open Split PDF and drop the file. Page thumbnails load after the file is added so the first paint stays the prerendered article.
- Choose By file size. Pick 1 MB, 2 MB, 5 MB, or type a custom megabyte value (for example 1.5).
- Click Split PDF. Download the ZIP when there are several parts. Open each part and check the last page of part 1 continues on part 2.
When a single page is larger than the limit
The tool does not skip that page and does not silently drop it. It writes that page as its own PDF and marks the row “over the chosen limit.” You then have three honest options: raise the cap, run that one-page file through the target-size PDF compressor, or tell the portal the scan will not fit at readable DPI. Lying with a 50 DPI flatten is worse than a clear flag.
Email and portal notes
- Gmail’s attachment cap is 25 MB; larger files become a Google Drive link (support.google.com/mail/answer/6584). Gmail measures that 25 MB limit before encoding (Gmail sending limits in Google Workspace), so a 20 MB file sends from Gmail. Receiving servers such as Outlook.com (25 MB per email) and many company mail servers count the encoded message, which is about 33–37% larger, so ~18 MB parts are safe for any recipient. Classic Outlook desktop defaults to 20 MB, so use ~14 MB parts there. The 14 MB and 18 MB buttons on Split PDF are those heads-up caps. A part never exceeds the number on the button, except a single page that is larger on its own.
- A “2 MB PDF” on a government form usually means the whole upload, not each page. Size mode is the right first cut; compress if even a single page overshoots.
- Reassemble later with Merge PDF if the other party wants one file after they have accepted the parts.
Need a chapter split instead of a size split? See split a PDF book into chapters and how to split a PDF into two files.
Frequently asked questions
Does split by size shrink the photos inside the PDF?
No. It only copies pages into new files. A page that is already larger than the cap becomes its own part and is labelled over the limit. Use the PDF compressor if you still need every page and fewer bytes.
What if one scanned page is bigger than 2 MB?
That page is saved as its own PDF and flagged. Split cannot invent a smaller encoding. Compress that page, or raise the cap.
Is this different from compress vs split?
Yes. Compress vs split is a decision guide. This post is the how-to for the size mode that now ships on Split PDF.