PDF guides6 min read
How to split a scanned batch into separate PDFs
You scanned a whole pile at once and got one giant PDF. Here's how to turn it back into one file per document using blank sheets.
You put thirty invoices through the feeder, pressed scan once, and got back one 68-page PDF. The scanner has no idea where one invoice ends and the next begins, so it did the only thing it could and stacked them all into one file.
Splitting that file every few pages won't work, because the invoices aren't all the same length. Splitting it by hand means reading every page, writing down the ranges, and running the split thirty times. That takes longer than the scanning did.
There's an old office trick that fixes this. Put a blank sheet of paper between each document before you scan. The blank pages end up in the PDF as markers, and the tool can find them and cut the file at each one.
It's not fully automatic, and that's on purpose. The tool shows you which pages it thinks are blank, and you get to fix its guesses before anything is saved.
When you might need this
- One scanner file with many documents in it is no good as a record.
- The documents are different lengths, so splitting every few pages won't work.
- Splitting a long batch by hand takes much longer than scanning it.
- Filing, searching and sending all work better with one document per file.
- Blank sheets cost nothing and work with any scanner.
How to do it
- Before you scan, build the stack like this: document, blank sheet, document, blank sheet, and so on. You don't need a blank sheet after the last one.
- Scan the whole pile in one go and save it as a single PDF.
- Open Split PDF, add the scan, and choose the blank separator page option.
- Click to find the separator pages. The tool checks every page and lists the ones that look blank, along with how sure it is.
- Go through the list. Untick any page that really belongs to a document, like an intentionally empty back page. If a gray scan hid some separators, change the threshold.
- Look at the grouped preview. Each group becomes one file. If a cut is in the wrong place, click the scissors between two pages to move it.
- If you want, tick the option to name each file from the text on its first page. Then export and download the files as one archive.
Free, with no account. Open it in a new tab and follow along.
Open Split PDFTips
- Use colored paper for the separators. It's easy to spot in the tray and impossible to miss in the thumbnails.
- A scan of blank paper is never pure white. That's what the threshold is for. Raise it if the tool misses separators in a gray or speckled scan.
- Keep the separator sheets next to the scanner and reuse them. Once they're there, it quickly becomes a habit.
- Scan at a medium resolution. 300 DPI works well for finding blank pages and for reading text. Higher settings just make the file slower to handle.
- If some documents have their own blank pages, look at the list carefully before you split. That's the exact case the review step is there to catch.
- Name the files from their first page when each document has a clear heading, like an invoice number. It saves you renaming thirty files by hand.
- Try it on a short test pile of five or six documents before you trust it with a full tray.
Common mistakes
- Forgetting a separator between two documents, so they end up in the same file. The grouped preview is where you'll spot this.
- Trusting the automatic detection without looking at the list, then finding out a month later that two invoices share a file.
- Setting the threshold so high that lightly printed pages count as blank, which cuts documents in half.
- Scanning in double-sided mode when the pages are single-sided. Every other page comes out blank and the batch gets chopped into pieces.
- Throwing away the original scan before checking the new files. Keep it until everything is filed.
How this compares to Smallpdf, iLovePDF and Adobe
Smallpdf and iLovePDF can both split PDFs, but only at page numbers you type in. Neither will find the blank sheets for you, so a scanned batch still means reading through it and typing ranges by hand.
Adobe's online tools can split every N pages or at top-level bookmarks. A scan has no bookmarks and the documents aren't all the same length, so neither option really fits.
Our tool checks every page, suggests where the separators are, and lets you correct it before anything is saved. The whole thing, including the optional text reading that names the files, runs in your browser. That matters here, because a scanner tray is usually full of invoices, contracts and letters you'd rather not upload.
| Criterion | Smallpdf | iLovePDF | Adobe Acrobat online | Easy File Tools |
|---|---|---|---|---|
| Where your file is processed | On their servers, after you upload it | On their servers, after you upload it | In Adobe's cloud, after you upload it | In your browser, on your own device |
| Account or sign-in | Asked for early, and needed once you pass the free allowance | Optional for small jobs, needed for bigger ones | Most online tools need an Adobe ID | Never needed |
| Usage limits | A few free tasks, then an upgrade prompt | Daily task and file limits on the free plan | The free web tools are mostly a preview of the paid plan | No task counters and no daily limits |
| File size ceiling | The free plan limits upload size | The free plan limits upload size | Cloud upload limits apply | We don't set one. Your device's memory is the practical limit |
| Works without a connection | No, their server does the work | No, their server does the work | No, the cloud does the work | Yes for the browser tools, once the page has loaded |
| Cost | Paid subscription for full access | Paid subscription for full access | Paid Acrobat subscription for full access | Free. Every tool is open to everyone |
Other services change their plans and limits often, so treat this as a rough picture and not a price list. Check their websites for the current details.
Frequently asked questions
- What if my documents have blank pages inside them?
- The tool will find those too, which would cut a document in two. That's why there's a review list. Untick any page that belongs to a document and the preview updates before you export.
- Can I keep the separator sheets in the files?
- Yes, there's an option for that. By default they're left out, since a blank sheet is just a marker.
- Does this work with a phone scan?
- Yes, as long as the photos are put together into one PDF and you photographed the blank sheets too. Phone scans usually have a darker background than a flatbed scanner, so you'll probably need to raise the threshold.
- What if two blank sheets end up next to each other?
- They're treated as one separator. Two sheets feeding together is a scanning slip, so you won't get an empty file.
- How are the files named?
- By default they use the original file name plus a number. If you tick the naming option, each file is named from the first useful line of text on its first page. If the scan has no text, the tool reads the page image to find it.
- Where is the PDF processed?
- In your browser. Checking the pages, splitting and reading the text all happen on your device.