How the range syntax works
Ranges are separated by commas, and each range becomes its own output file. Typing 1-3,5 creates two PDFs: one with pages 1 to 3 and one with page 5 alone. Typing 1-3,4-6,7-10 splits a ten page document into three files.
A single number means that one page. A dash joins a start and an end page, both included. Page numbers refer to the position in the file, not the number printed in the corner, so a document with a cover and roman numeral front matter may need a small adjustment.
Spaces around commas are fine, so 1-3, 5 works the same as 1-3,5. If a range goes past the last page of the document, the tool will point it out rather than guess what you meant.
Ranges cannot be written backwards. If you want pages in reverse order, split them first and then use the organize PDF tool to rearrange the result.
Splitting every page
Choose the every-page option when you want a separate PDF for each page. This suits scanned stacks of receipts, single-sheet certificates or a batch of forms you need to hand out individually. A 30 page file gives you 30 PDFs, all inside one ZIP.
File names in the ZIP are numbered in order, so they sort correctly in your folder.
Splitting versus extracting
Splitting produces multiple files at once. If you want one new PDF made from scattered pages, such as 2, 7 and 9 together, the extract pages tool is a better fit. If you only want to throw pages away, use delete pages.
A common pattern is splitting a long contract into sections so that each department receives only the part it needs. Another is dividing a textbook scan by chapter so it is easier to open on a phone.
Think about who will receive the file. If three different people each need a different section, split. If one person needs a custom selection, extract. Picking the matching tool means less cleanup afterward.
Limits to keep in mind
The PDF can be up to 100 MB. Encrypted or password-protected files are not supported, so remove the password elsewhere first. Output pages are copied directly, so quality, fonts and links are unchanged.
If the resulting parts are still too large to send, compress them one by one. Pages with high resolution photos are usually the biggest contributors.
Large scanned books deserve a little planning. Decide on the chapter boundaries first, write them down as ranges, and enter them all at once. That is faster than running the tool several times, and it keeps the output files consistently named.