Clean Up Scanned PDF
Enhance scanned PDFs with contrast boost and black-and-white threshold. Free and private in your browser.
Make gray scans crisp and printable
Phone scans often look washed out. Contrast stretch plus a B/W threshold turns muddy gray into sharp black text on white — processed entirely on your device.
What you can do with it
- Prepare scans for OCR
- Higher contrast usually improves text recognition.
- Clean receipts before filing
- Remove gray backgrounds that waste toner.
How to clean up a scanned PDF
- Open your scanned PDF — it loads locally with no upload.
- Set the B/W threshold if needed.
- Click Clean scan & download.
Threshold tuning
Start near 160. If gray paper remains, raise the threshold. If thin glyphs disappear, lower it. Always keep the original scan.
OCR-friendly output
High-contrast B/W pages usually OCR better. Run OCR PDF after cleanup when you need searchable text.
Related reading and tools
- OCR PDF — Make cleaned scans searchable.
- Convert PDF to grayscale — Softer desaturation without hard thresholding.