Split a PDF by file size

Because splitting does not touch the content. Strong compression redraws every page as an image, so a scanned contract comes back with smeared letters and may not be accepted at all. Splitting copies the pages as they are, so what you download is the page that went in, at full resolution. Try light compression first, and if the file is still over the limit, splitting is the answer that costs you nothing in quality.

Because nothing here is estimated. A PDF's size is not the sum of its pages: an embedded font or a repeated image is stored once however often it is used, so ten pages together are far smaller than ten separate files. Every candidate part is therefore actually written and its bytes counted, and the size shown next to each part is the size of the file you will download.

As few as possible. Each part is filled with the most consecutive pages that keep it under the limit before the next one starts, so no part comes out half empty. The file names carry their page numbers, like part-2-pages-13-24, because you are most likely about to upload them one at a time into a form that asks which pages are in which.

Splitting has no answer for it: the smallest possible part is one page. That page goes out as its own part and is marked in the result list with its size, so you do not upload it and get rejected without knowing why. The fix for it is compression or a lower image resolution inside it, and it is usually a page scanned at a very high DPI.

Page content travels exactly as it is, but anything attached to the document as a whole does not: the outline, bookmarks and filled form fields belong to the document rather than to a page. If you have a filled form, run it through the flatten tool first, so the answers become permanent page content and nothing is lost.

No. Reading, measuring and writing all happen inside your browser on your own device, and the file never leaves it. You can disconnect from the internet after the page loads and the tool still works.