How to Get a PDF Under an Email or Upload Size Limit

Updated: 10 September 2026

"Your file exceeds the maximum size" is one of the most common walls people hit with a PDF. The fix depends on why the file is big, so this is a short order of attack: work down the list until you clear the limit, starting with the change that costs you the least.

First, know what the limit is

Two limits look the same but need different answers. A per-file limit — "each attachment must be under 5 MB" — can be met by splitting a big document into smaller files. A total limit — "the whole upload must be under 5 MB" — cannot, and needs the file itself to get smaller. Common ceilings worth knowing: most email services cap a message at around 25 MB, and many government and exam upload forms are far stricter, often 1 MB or 2 MB per file.

The order of attack

1. Compress the images. If the PDF contains scans or photographs, this is the biggest single win — Compress PDF re-encodes the embedded images at a lower quality while leaving the text untouched. A photo-heavy file can drop by ninety per cent; a text-only one will barely move, which tells you to try the next step instead.
2. Delete pages you don't need. In a scanned document every page weighs as much as any other, so dropping blanks, cover sheets or duplicate scans with Delete PDF Pages can cut the size sharply.
3. Split the file if the limit is per-attachment. Split PDF turns one oversized document into several that each clear the ceiling — useful when the recipient just needs the pages, not one bundle.
4. Strip the metadata. A smaller saving, but free, and worth doing anyway for privacy — Remove PDF Metadata clears author details and editing history the file has been carrying around.

When the numbers simply don't work

If a form demands 200 KB and you are holding a 40-page colour scan, no honest compressor will get there without turning the text to mush. At that point the realistic moves are to cut the page count, re-scan the document at a lower resolution (150 DPI in greyscale is usually plenty for text), or check again whether the limit is really per file rather than per upload. Compressing past the point of readability just means submitting a document nobody can read.

Why not just a ZIP?

Zipping a PDF barely helps. The heavy part of a PDF is its images, and those are already stored in compressed form inside the file, so a ZIP finds almost nothing left to squeeze — and many upload forms reject .zip files anyway. Shrinking the PDF itself, with the steps above, is what actually moves the number. For the full picture of where PDF weight comes from, see how PDF compression works.