“Splitting a PDF” usually means one of two different things, and it’s worth being clear about which one you actually need before you start.
Problem 1: You need every page as its own file
Common when you’ve scanned a stack of documents as one PDF and now need to file each page separately — say, twenty invoices that got scanned together as a single 20-page PDF. Split PDF has a “split into single pages” mode that does exactly this: one PDF in, N single-page PDFs out, zipped up for you to download in one go.
Problem 2: The file itself is too big to upload or email
This is a size problem, not a page-count problem. If a portal caps uploads at, say, 10MB and your PDF is 35MB, you don’t necessarily want 40 separate one-page files — you want it broken into two or three chunks that each fit under the limit. The same tool has a “split by file size” mode for this: tell it the limit, and it works out how many pages can fit in each chunk. However many chunks that ends up being, you can download them one at a time or grab them all in a single ZIP.
Before splitting for size reasons, it’s often worth trying Compress PDF first — if compression alone gets you under the limit, you keep one file instead of several, which is usually easier for whoever’s on the receiving end.
Problem 3: You need a specific page range, not the whole thing
If what you actually want is just pages 3 to 8 as their own file, splitting into single pages or size-based chunks is more work than the job needs. Split PDF also has a “Custom pages” mode for exactly this: type a range like “3-8”, or several at once comma-separated (“1-3, 5, 8-10”), and each group downloads as its own file — no need to touch every other page. List multiple ranges and the same “download all as ZIP” option covers those too, so listing five ranges doesn’t mean five separate download clicks.
There’s no cap on how many pages a range can cover or how many ranges you list — it all runs in your browser, so the only real ceiling is your device’s own available memory, not a page count we impose.
A less obvious use: splitting by content, not just page count
If your PDF has a repeating marker — like “Invoice #” appearing at the start of every invoice in a batch-scanned document — Split by Text can split the file at each occurrence automatically, rather than you counting pages by hand. And if the PDF already has bookmarks (a table of contents baked into the file, common in reports and books), Split by Bookmarks turns each top-level bookmark into its own file, named after the bookmark itself.
It works the same way on your phone
Because nothing gets uploaded, there’s no separate mobile app to install and no desktop-only limitation — the tool runs the same way in Safari on an iPhone or Chrome on Android as it does on a laptop. Tap to upload from Files or your device’s storage, pick whichever mode you need, and download the result the same way. The one place a phone can fall behind a desktop is memory: an unusually large scan (say, several hundred pages of photographed documents) is more likely to run into a phone’s tighter memory ceiling first. There’s still no page-count limit either way — just whatever memory your device has free at the time.
Split too far, or need to recombine a couple of pieces?
If you’ve ended up with more files than you actually needed — or you split by mistake and want a couple of the pieces back together — Merge PDF does the reverse. Drop in any of the files you just split out (or any other PDFs), arrange them in the order you want, and it combines them back into one document.
Whichever way you need it split, none of it requires uploading the file anywhere — it’s processed on your device, in your browser.