Split a PDF into parts under a size limit

Mail servers reject a 40 MB attachment, and portals often cap uploads at 10 or 20 MB. Set a maximum size and this tool cuts the document into consecutive parts that each come in under it, packing as many pages into each part as will fit. It runs in your browser, so a large confidential document never has to be uploaded just to be divided up.

How to split a PDF by file size

  1. Add the PDF

    Drop the oversized document in; its total size is shown.

  2. Set the size limit

    Enter the ceiling in megabytes — whatever the email or portal on the other end accepts.

  3. Split and download

    Press Split. Each part is filled to just under the limit and the whole set arrives as a ZIP.

What Split PDF by Size can do

  • Fills each part

    Parts are packed as full as the limit allows, so you get the fewest files.

  • Page order preserved

    Parts are consecutive and numbered, so reassembling them is trivial.

  • One ZIP download

    However many parts it takes, it's a single download.

  • Private

    Splitting happens locally — no upload, which is the whole point when the file is sensitive.

Split PDF by Size — frequently asked questions

How do I email a PDF that's too large?

Two options. Compress PDF first — often that alone gets it under the limit. If it's still too big, split it here into parts under your provider's cap and send them separately.

What if a single page is bigger than the limit?

That page becomes its own part, since a page can't be cut in half. Compress the PDF first to bring individual pages down.

Can I put the parts back together later?

Yes. The parts are numbered in order — drop them into Merge PDF in that order and you get the original document back.

Do my PDFs get uploaded to a server?

No. Every tool on Notoo Tools runs as JavaScript and WebAssembly inside your browser tab. There is no server that receives your files — you can disconnect from the network after the page loads and the tool keeps working.

Do I need an account or a subscription?

Neither. There's no sign-up, no email, no free-tier limit and no watermark. Bookmark the tool and it opens straight into the work.