How to Detect Blank Pages in a PDF Online

A duplex scan of a stack of single-sided documents fills the PDF with blank back-sides. A merged report from three sources has empty spacer pages no one needs. Spotting them by hand on a 300-page file is tedious; an automatic detector flags them in two seconds.

When you actually need Detect Blank Pages

Duplex scans, merged reports, exports from publishing tools that include blank chapter dividers, PDFs from legacy systems that pad to even page counts.

How to detect blank pages, step by step

Open the tool

Go to convertpdfgo.com/detect-blank. No account, no email, no installation.

Drop the PDF in

Drag the file onto the upload area or click to pick. Files up to 30 MB go through without a queue. Encrypted in transit (TLS 1.3), encrypted at rest, deleted within one hour.

Configure your run

Nothing to configure — detection runs with a sensible default threshold.

Download

The output is a clean PDF — open in any reader.

Common problems and how to avoid them

False positives on almost-blank pages

Pages with just a page number flag as blank with our default threshold. Tighten the threshold if you want pages-with-only-a-number kept.

False negatives — page looks empty but isn't flagged

Hidden whitespace characters or a faint background watermark may keep the coverage above the threshold. Eyeball the page in the original PDF.

Detection runs but output is just a list

By design — we don't modify the input. Feed the list of page numbers into Remove Pages.

A short word on privacy

Three things to know. One: files go over TLS 1.3. Two: files are encrypted at rest while we process them, then deleted automatically within one hour. Three: we don't look at your files or train on them.

How we compare to other free tools

Feature	convertpdfgo	Smallpdf	iLovePDF
Sign-up	None	After 2/day	Optional
Watermark	None	None	None
Auto-delete	1 hour	Vague	2 hours

Frequently asked questions

Will it count a page with a tiny mark as blank?

We use a coverage threshold — pages with less than ~1% pixel coverage are flagged. Pages with a header alone usually aren't flagged.

Can it auto-remove the blanks?

Not in one job. Use the page list as input to Remove Pages — that does the deletion.

Are my files private?

Files are encrypted in transit (TLS 1.3) and at rest, then auto-deleted within one hour.

Will it work on protected PDFs?

Not directly — unlock the PDF first with our Unlock PDF tool if you know the password.

Is there a usage limit?

No. Free, no daily cap, no sign-up wall, no watermark.

How long does it take?

About 1-3 seconds for most files. Larger or image-heavy PDFs can take up to 30 seconds.

What's the file size limit?

30 MB as a guest, 50 MB when signed in.

What to do next

Now you can Remove Pages, Inspect PDF, or Compress PDF. All free.

Or browse our full list of 49 free PDF tools.