Skip to main content
VellumPDF

Split a PDF by size

No more rejected attachments: every chunk stays under the limit.

Your files never leave your device

Drop your PDF here

or click to browse your files

How to split a PDF by size, step by step

This tool cuts a document into several chunks that each stay under a size limit you choose — useful for an email attachment or an upload portal.

  1. Drop your PDF

    Drag the file onto the drop area, or click to browse for it.

  2. Choose the maximum size per chunk

    A preset of 5, 10, 20 or 25 MB, or a free value in the number field.

  3. Click “Split by size”

    VellumPDF looks, for each chunk, for the largest number of consecutive pages whose actually exported file stays under the limit — the size is measured, not estimated.

  4. Download the archive

    The chunks are delivered in a ZIP file, with a summary of the pages and weight of each one.

A single page that already exceeds the limit on its own forms its own, oversized chunk and stays flagged in the summary: it then needs to be slimmed down separately, for example with compression.

Frequently asked questions

How do I split a PDF that is too large for an email attachment?

Choose a maximum size — 5, 10, 20 or 25 MB — and VellumPDF cuts the document into several chunks that each stay under that limit, delivered in a ZIP archive.

Is each chunk’s size estimated or precisely measured?

Every chunk is measured on the file actually exported, not estimated. A single page too heavy to fit under the limit on its own forms its own chunk and stays flagged.

Is this size-based split free and processed locally?

Yes, the split is computed in your browser, without the document ever leaving your device, free of charge and unlimited.

How does the split hold exactly to the limit you set?

It does not estimate it, it measures it. For each chunk the tool uses a binary search to find the largest run of consecutive pages whose actually exported PDF stays under the limit, weighing the produced file at every attempt. That is slower than a rule of three on page counts, but it is the only method that does not let you discover the overshoot at upload time.

What happens if a single page exceeds the limit on its own?

It becomes its own chunk and you are told, with the page number. It happens with a high-resolution scanned plan or a full-page photo. Splitting cannot help there: that page has to be made lighter first, by compressing it or lowering the scan resolution.

Which limit should I choose for an online upload?

Take the stated limit minus a margin: a portal that accepts 10 MB sometimes rejects a 9.9 MB file once the upload is encoded. Splitting at 8 or 9 MB saves the second attempt. And check whether the limit applies per file or to the whole submission — they are not the same thing.