Delete blank pages from a scanned PDF

The job

Duplex scans of single-sided originals interleave a blank for every real page; exports sometimes pad to even page counts. The tool renders each page at low DPI, measures ink coverage — the fraction of pixels darker than near-white — and removes the pages under your threshold.

Cleaning a scan

Choose the PDF, set the threshold (0.1% is a sensible default — a truly blank scan sits near zero), and check the per-page coverage preview before saving. The preview shows exactly which pages will go and why.

• Coverage counts pixels darker than the threshold — a stray speck of dust or scanner line can push a 'blank' page above 0.1%; nudge the threshold rather than rescuing by hand.
• Encrypted, signed, and form PDFs aren't supported; up to 25 MiB and 100 pages.
• Keep at least one page — the tool refuses to delete all of them.

Where it stops

Detection is luminance-based: a page with a faint stamp or full-page colour background won't read as blank, and faint pencil text can read as blank. The preview exists precisely so you can catch those before deleting — check it, don't trust it blind.