Convert a PDF to grayscale
Make a PDF black & white (gray) to reduce size and printing ink.
Convert PDF to grayscale (complete guide)
Grayscale conversion removes color information and keeps only shades of gray. It’s a practical optimization when you want smaller files, faster downloads, and cheaper printing. It’s especially effective on scanned documents that were saved in color even though the content is mostly black text.
When grayscale helps
- Scanned paperwork: invoices, contracts, forms, receipts.
- Email attachments: smaller files without aggressive compression artifacts.
- Printing: less ink and more consistent output.
When NOT to use grayscale
- Charts where color encodes meaning (red/green comparisons, heatmaps).
- Brand materials that require color accuracy.
Best workflow for size reduction
- Convert to grayscale first.
- Then run Compress PDF on Medium.
- Verify readability at 100% zoom, especially small text and signatures.
Suggested workflow
- If you only need a subset, use Extract pages first.
- Convert to grayscale.
- Optionally remove document properties with Remove metadata.
- Optionally protect with Protect PDF for sharing.
Privacy & retention
Files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours).
Troubleshooting
- File size didn’t change: the PDF may already be optimized; try Compress PDF after grayscale.
- Text looks worse: your PDF is likely a low-quality scan; avoid aggressive compression afterward.
- Encrypted PDF: unlock first with Unlock PDF.
How it works
- Upload a PDF.
- Process.
- Download the grayscale PDF.
FAQ
Will it remove colors?
Yes — colors are converted to grayscale. Check charts/graphs if color matters.
Will this reduce file size?
Often, especially for scanned documents. For best results, grayscale first then compress.
Does grayscale reduce quality?
It removes color, but it should keep text readable. Always verify critical pages.
Should I compress after grayscale?
Yes — grayscale first, then Compress PDF (Medium is a good default).
Can I grayscale only some pages?
Not yet. If needed, extract pages first, grayscale, then merge back.
Will it change page order?
No.
Can I grayscale a password-protected PDF?
Only after unlocking it (requires the password).
Does this remove metadata?
No. Use Remove metadata for document properties.
Can I convert pages to images after grayscale?
Yes — use PDF to JPG/PNG/WebP.
How long are my files stored?
Files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours).
Related tools
Privacy note: files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours).