Runs in your browser · nothing is uploaded

Overlay PDF

Overlay PDF pages on top of or behind another PDF — letterhead under a letter, a form background under filled-in text, or a stamp over every page. Choose which pages, how it's scaled and how see-through it is, then download.

Base PDF · The document to add to

Overlay PDF · Letterhead, stamp, form background…

The overlay pages are embedded as vector drawings, so text stays sharp and selectable. Both files stay on your device.

How it works

Overlaying a PDF

Open the base PDF (the document) and the overlay PDF (letterhead, stamp or background). Both are read on your device.
Choose whether the overlay goes on top or behind, and which overlay page goes on which base page.
Pick the size and alignment, and the opacity. The preview shows the real result for any page.
Download. The overlay pages are embedded with pdf-lib and the file is saved as name-overlay.pdf.

Which pages get the overlay

First overlay page on every page — letterhead, a logo, a stamp.
Page 1 on the first page, page 2 on the rest — letterhead with a continuation sheet.
Page by page (1 → 1, 2 → 2 …) — base pages past the overlay's last page are left alone.
Repeat the overlay pages in turn — 1, 2, 1, 2 … for odd and even pages.
Chosen pages — one overlay page on the base pages you list.

Limitations, plainly

Behind can be hidden. If the base pages paint a solid white background, an overlay behind them won't show. Use On top with Multiply instead.
Only the page drawing is used. Comments, links and form fields on the overlay PDF aren't copied; those on the base PDF are kept.
Blank overlay pages are skipped, and base pages with nothing mapped to them are left exactly as they were.
Digitally signed base PDFs will show their signature as invalid after any change, including this one.
Password-protected PDFs can't be opened — remove the password with Unlock PDF first. Up to 200 MB and 2,000 pages per file.

Frequently asked questions

Are my PDFs uploaded anywhere?+

No. Both PDFs are opened and combined entirely in your browser, and the result is saved straight to your device. Nothing is sent anywhere or stored.

How do I add letterhead to a PDF?+

Open your document as the base PDF and your letterhead (a PDF with just the logo, address and footer on an otherwise empty page) as the overlay. Choose “First overlay page on every page”, or “Page 1 on the first page, page 2 on the rest” if your letterhead has a separate continuation sheet. Check the preview and download.

Should the letterhead go behind or on top?+

Behind is the natural choice: the letterhead is drawn first and your document's text on top of it, as if printed on headed paper. It only works if the base pages are see-through — many PDFs exported from Word or scanned paper have a solid white background that hides anything behind it. If the letterhead disappears in the preview, choose On top and tick Multiply: white parts of the letterhead then let the page show through, and its ink darkens what's under it.

What happens if the two PDFs have different page sizes?+

Each overlay page is scaled to each base page on its own. Fit keeps the overlay's shape inside the page, Fill covers the whole page (cutting off what sticks out), Stretch matches both sides exactly, and Actual size keeps it as it is. Alignment decides where it sits. Rotated pages are handled, so the overlay appears upright as you see the page.

Is the overlay turned into an image?+

No. Each overlay page is embedded as a vector drawing (a PDF form object) and drawn on the pages you choose, so text stays sharp and selectable, and an overlay used on many pages is stored only once.

Why can't I open my PDF?+

Password-protected or encrypted PDFs can't be used here. Remove the password first with Unlock PDF (tools.northlane.live/unlock-pdf/).

What's the difference between an overlay and a watermark?+

An overlay takes whole pages from another PDF — letterhead, a form background, a stamp designed in another app — and places them as vector drawings. A watermark is text or a single image you set up on the spot. For a quick “CONFIDENTIAL” or a logo, Watermark PDF (tools.northlane.live/watermark-pdf/) is simpler.

Can I use different overlay pages for odd and even pages?+

Yes. Use a two-page overlay and choose “Repeat the overlay pages in turn”. On a five-page document the overlay pages go 1, 2, 1, 2, 1, so overlay page 1 lands on the odd pages and page 2 on the even ones.

Can I add the overlay to only some pages?+

Choose “Chosen pages”, type the base pages, such as 1, 3-5, and pick which overlay page to use. “Page by page (1 → 1, 2 → 2 …)” puts overlay page 1 on page 1, page 2 on page 2 and so on, and leaves base pages past the overlay's last page untouched.

My letterhead is a Word file or an image. Can I use it?+

The overlay has to be a PDF. Save the Word file as a PDF (File › Save As › PDF), or turn a PNG or JPG into a PDF with JPG to PDF (tools.northlane.live/jpg-to-pdf/), then open that PDF here as the overlay.

Can I make the overlay see-through?+

Yes. Opacity goes from 5% to 100% in 5% steps, which suits a faint background or a light stamp. With the overlay on top, Multiply also lets its white areas disappear so the page shows through.