Overlay One PDF Onto Another
Stamp letterhead, watermarks, or approval marks from one PDF onto the pages of another — right in your browser.
Drop your base PDF here
The document you want to stamp or add letterhead to
Drop your overlay PDF here
Letterhead, watermark, or stamp — only the first page is used
About PDF Overlay
PDF Overlay lets you stamp one PDF onto the pages of another, entirely in your browser. It's built for adding company letterhead, watermark backgrounds, or approval stamps like 'PAID' to existing documents without touching the original page content. Choose exactly which pages get the overlay, whether it sits on top or behind your content, and how transparent it should be.
Features:
- Apply to all pages, a page range, or just the first page
- Choose whether the overlay sits on top of or behind your content
- Adjustable opacity for subtle watermarks or bold stamps
- Privacy-first — files never leave your device
How to Overlay a PDF
- Upload your base PDF — the document you want to stamp
- Upload your overlay PDF — the letterhead, watermark, or stamp
- Choose which pages to apply it to, the layer order, and opacity
- Click Apply Overlay to download your combined PDF
Frequently Asked Questions
Will this work on password-protected PDFs?
No. Remove the password from both PDFs first, then upload them here.
Does the overlay affect the original files?
No. Your base and overlay PDFs are never modified or uploaded — a brand-new PDF is created with the overlay applied.
Can I use an image as the overlay instead of a PDF?
Not directly — convert your image to a single-page PDF first (see our Image to PDF tool), then use it as the overlay.
What's the difference between overlay and merge?
Merging stacks PDFs page after page in sequence. Overlay stamps one PDF's content directly onto the same pages of another, combining them into a single layered page.
What happens to pages I don't select?
Pages outside your chosen range are copied over unchanged, with their original quality and any links or form fields intact.
Can I put the overlay behind the text instead of on top?
Yes — switch the layer order to 'Overlay underneath' and it will sit behind your document's content, like a background watermark, rather than covering it.
Privacy
Both PDFs are processed entirely in your browser using JavaScript. Nothing is uploaded to any server — your documents stay on your device.