How to split a PDF here
Splitting comes down to three choices: how to cut, which pages, and how you want the files back.
- Add the PDF by dropping it on the box or using Choose PDF. The tool works on one document at a time; adding another replaces the first.
- Pick a mode under How to split: Ranges, Extract, Delete, Every N, By size, Bookmarks or Every page. The line beneath says what that mode will do.
- Tell it which pages: type ranges, tick thumbnails, enter a number of pages per file, set a size limit, or choose how deep in the bookmarks to cut.
- Read the plan. A table lists every file that will be created, with its name, pages and size, and each page in the grid gets a coloured edge showing which file it goes to. Pages that go nowhere are marked “not included”.
- Choose One ZIP or Separate files under Download, then press Split into N files, or Save the new PDF when there is only one. A progress bar with a Cancel button follows the work.
To see how a mode behaves before using your own document, Try with a sample PDF loads a short report with chapter bookmarks.
What happens to your PDF: it stays on your device
The PDFs people split are often the ones they least want to hand to a stranger: a year of bank statements, a scanned pile of medical letters, a contract with its schedules. Here the file is read into this tab’s memory, cut apart by code running in the tab, and the new PDFs come back as downloads. No request carries the file, its name, its page count or its size.
What the page does fetch, the first time you add a file, is its own machinery: pdf.js (Mozilla’s PDF reader) to draw pages and read bookmarks, pdf-lib to write the new files, and a small ZIP library. If that download fails, a retry message appears and your PDF stays open. Checking takes about a minute:
- Press F12 (Cmd+Option+I on a Mac) and open the Network tab.
- Add your PDF and split it. You will see the tool’s code from dothecalculation.com and the consent and analytics scripts every page on the site loads, including the page-view record of which page you opened. None carries your PDF or its name, and none is the size of your file.
- Once a file has been added, the tool’s parts are loaded, so you can switch on airplane mode, add the PDF again and split it. It still works, because nothing has to leave the device.
Our guide Are online PDF converters safe? explains what uploading a document to an online tool involves and how to run the same test anywhere.
Ranges, Extract and Delete: three ways to say which pages
Ranges is for when you know the page numbers. Every part you type, separated by a comma, a semicolon or a new line, becomes a file of its own: on a 20-page document, 1-3, 4-10, 11- gives three files. The box understands:
- 7 for one page, and last for the final page whatever the count.
- 4-10 for a run of pages; typed backwards, 10-4 gives the same pages in normal order.
- 11- or 11-end for page 11 to the end, and -3 for pages 1 to 3.
- odd and even for every odd or every even page, as one file.
Parts may overlap, and each is checked against the page count before anything is written: on a 40-page file, a part asking for 38-45 is named in a message, and every faulty part is listed, not only the first. Switch on Put all ranges in one file and you get a single PDF holding only the pages you typed, in document order, so 1-2, 5, 9-10 makes one five-page file.
Extract is for when it is easier to point than to count. Tick pages with the box under each thumbnail, or press Space on the selected page; Tick all and Clear ticks help on long documents. The ticked pages become one new file, or a file each with One file per ticked page switched on.
Delete is Extract turned inside out. Tick the pages you want gone and the rest is saved as one new file with -edited added to the name, so lease.pdf becomes lease-edited.pdf and the original is untouched. Ticking every page is refused, since a PDF needs at least one. Typical jobs: a blank page the scanner slipped in, a fax cover sheet a portal does not want, or an appendix of personal details.
Deleting removes whole pages; it does nothing to the pages you keep. Details hidden under a black box drawn in another program can still be in the file, and blacking out properly needs a redaction tool.
Split by size: parts that fit an email or upload limit
Email services and upload portals refuse files over a set size. When we read their help pages in September 2026, Gmail allowed 25 MB of attachments from a personal account, Outlook.com and Yahoo Mail 25 MB, and US immigration’s online filing 12 MB per file. Limits change, so check the provider’s own page; How to send a large PDF has the full table with sources.
Two details catch people out. A mail limit usually covers all the attachments in one message together, so five 9 MB parts go in five emails. And some mail servers, Microsoft Exchange among them, measure a message after its attachments are encoded for sending, which Microsoft says adds about 33%. If a part near the limit bounces, plan again with a lower figure.
Enter the limit in Largest part (MB) and press Plan the split. The tool does not guess from the page count, because pages differ enormously: a page of typed text can be a few kilobytes and a colour scan several megabytes. Instead it builds real PDFs from runs of pages and weighs them.
The search doubles, then halves. From page 1 it checks whether everything left fits. If not, it tries a run of 2 pages, then 4, then 8, until a run is too heavy. The answer lies between the last run that fitted and the first that did not, so it tries the middle of that gap, then the middle of what remains, until one length is left. That is part 1, and the search restarts on the next page, costing a handful of measurements per part rather than one per page.
In our test, a 17-page, 40.7 MB scan at 300 DPI with a 10 MB limit was planned in 0.6 s as five parts of 9.2, 9.1, 9.1, 9.1 and 2.3 MB. In this mode the plan shows each part’s measured size; other modes show an estimate marked ≈.
Splitting cannot make a page smaller. A page over the limit on its own goes into a part by itself, with a warning. Run the file through Compress PDF first, then split the smaller file; How to reduce PDF file size explains why scanned pages get so heavy. The limit counts 1,048,576 bytes to the megabyte, as Windows does; a Mac’s Finder counts 1,000,000, so the same part looks about 5% bigger there.
Split by bookmarks: one file per chapter, statement or invoice
Many PDFs carry an outline: the bookmarks a PDF reader lists beside the pages. Word builds one from headings when you save as PDF, and systems that produce batches of documents often bookmark each one. In Bookmarks mode, every bookmark starts a new file that runs to the page before the next one, named after the bookmark.
That makes quick work of a report cut into chapters, a month of invoices exported with a bookmark per customer, a year of statements bookmarked by month, or an evidence bundle with a bookmark per exhibit. Pages before the first bookmark, such as a cover and contents page, become a file called Front matter.
Split at offers two depths. Top-level bookmarks (chapters) cuts only at the outermost entries. Top two levels (chapters and sections) also cuts at the entries one step in, so a chapter with three sections becomes three files, or four when the chapter has an opening page before its first section. Two bookmarks on the same page make one file, named after the first. Deeper entries stay inside their file as bookmarks.
In our test, a 200-page PDF with a three-level outline, split at the top level, became 10 files of 20 pages in 0.7 s, each keeping its own 9 bookmarks. Each part’s document title is set to its bookmark, so a reader’s title bar shows the chapter rather than the whole book.
If the PDF has no bookmarks, the tool says so and points you to Ranges or Every N pages. Scans almost never have any; take the start pages from the contents page and type them as ranges instead.
Every N pages, and one file per page
Every N cuts a document into equal parts. Enter the number in Pages in each file and the line beneath shows how many files that makes; the last part takes whatever is left, so 50 pages in parts of 4 give twelve files of 4 and one of 2. It suits a pile of same-length documents scanned together, such as 30 two-page application forms in one 60-page scan, and a long text sent out in even portions, such as a manuscript going to readers 50 pages at a time.
Every page makes one PDF of each page, named with its number, such as payslips-page-07.pdf. It is the mode for documents where each page stands alone: a year of pay stubs exported as one file, certificates generated together for a class, receipts scanned one per page. To do the same for only some pages, use Extract with One file per ticked page.
What each new PDF keeps, and what changes
Splitting copies pages into new files; it does not redraw them. For each part:
- Page size and rotation: every page keeps its own, so an A3 drawing inside an A4 report stays A3, and a turned page stays turned.
- Text: still real text you can select, search and copy. Nothing becomes an image.
- Images and fonts: copied exactly, with no recompression. Each part carries the fonts its pages use, so ten parts can add up to more than the original: a font stored once in the original is stored once in every part.
- Annotations: comments, highlights and stamps stay on their pages.
- Links: a link to another page keeps working when that page is in the same part; otherwise it is removed, and the result says how many were. Links to websites are unaffected.
- Bookmarks: each part keeps the ones pointing at its own pages, renumbered. Others are left out, and entries nested under them move up a level instead of disappearing.
- Form fields: flattened. A field’s value belongs to the document-wide form, not to a page, so it cannot stay fillable once its page moves to another file. The current answers are drawn onto the page and the result says how many fields were flattened, so fill the form in before splitting.
- Digital signatures: invalid in every part, because a signature covers the exact bytes of the signed file. When the PDF has a signature field, the tool warns you and waits for you to tick I understand. Send the signed original alongside the parts where it matters.
- Password: kept on each part if Keep the password on each part is on.
File names, ZIP files and phones
Names come from the original file and the pages each part holds, with numbers padded by zeros so files sort in page order. For a 40-page report.pdf:
- A run of pages: report-pages-01-03.pdf.
- One page: report-page-07.pdf.
- Scattered pages in one file: report-pages-01-03_07_09-10.pdf, or report-12-selected-pages.pdf when the list would make an unwieldy name.
- Bookmarks: report-01-Introduction.pdf, report-02-Methods.pdf, in the order the chapters appear.
- Delete mode: report-edited.pdf.
A document of 100 pages or more gets three digits, as in report-page-007.pdf. Characters Windows forbids, such as a colon or a question mark, are replaced and spaces become hyphens, so names work on Windows, macOS, Android and iOS; two parts that would share a name are given different ones.
One ZIP, the default, packs every part into one download such as report-split.zip. Separate files lists each part with its own download button, handier when you need two parts out of twelve. The finished list stays on the page, so a part can be downloaded again without splitting again.
On an iPhone, the ZIP lands in Downloads in the Files app; tap it and it unpacks into a folder of PDFs. On Android, open Files by Google, tap the ZIP in Downloads and choose Extract. To send one part from a phone, Separate files saves the unzipping.
Splitting a batch scan back into documents
A scanner with a document feeder takes a whole pile in one pass and hands back one long PDF: two letters, a bank statement and a tax form, one after another. To separate them, scroll through the thumbnails, click any page you are unsure of to see it large, and note where each document starts. Then type one range per line in Ranges mode. For letters on pages 1-2 and 15, a statement on 3-8 and a form on 9-14:
- 1-2
- 3-8
- 9-14
- 15
The coloured edges show each boundary, and the line under the preview names the file the current page will go to, so a misplaced cut shows up before you split.
Double-sided scanning of single-sided paper leaves a blank back after every front. When all the backs are blank, type odd as the only range to get one file of the fronts; when only some are, use Delete and tick the blank ones.
Fronts and backs scanned in two passes need interleaving, not splitting: Merge PDF alternates a fronts file with a backs file. If both passes ended up in one PDF, split it at the halfway point first (1-6 and 7-12 for 12 pages) and give Merge the two halves. Sideways pages keep their rotation when split; turn them upright with Rotate PDF.
Password-protected and restricted PDFs
A PDF that needs a password to open asks for it on the page. With the right one it splits like any other; the password is held in this tab’s memory while you work and is never stored or sent.
By default each part keeps the same password, encrypted with AES-256, so the pieces of a protected document stay protected. Switch off Keep the password on each part to get parts that open freely, for instance for an upload portal that refuses protected files, and only where they are going somewhere you trust.
Some PDFs open without a password but carry restrictions set by their author. When those forbid taking pages out, the tool stops with a message; ask the sender for an unrestricted copy. The tool does not guess passwords or remove protection from files you cannot open, and the site has no “unlock PDF” tool.
Your data
Only your choices are remembered: the mode, pages per file, size limit, the one-file toggles, delivery and whether to keep a password. They sit in your browser’s local storage under dtc.filetools.v1. Your PDF, its name, the ranges you typed, the pages you ticked and any password are never saved, and closing the tab clears the document from memory.
General information about splitting PDF files. Size limits and file rules for email and upload portals are set by each provider and change over time, so check the current requirements of the service or office you are sending the parts to.