Overlay / Underlay

Overlay PDFs online, free: add letterheads, stamps and watermarks as an upper or lower layer. Processed locally.

Places a layer file onto a base document — the standard technique for applying consistent letterhead, stamps, headers and footers, or for pre-printed form alignment.

Choose whether the layer sits above the content (a watermark) or below it (a background template). If the layer has fewer pages, it can loop to cover the rest.

Everything runs locally in your browser — nothing is uploaded to any server.

How to use

1. Pick two documents — Set the base document and the layer document.
2. Choose the mode — Overlay (above) or underlay (below), plus the page range to apply.
3. Apply and download — Click Apply to generate the overlaid PDF.

Related tools

• Merge PDF — Combine multiple PDFs in order into one file
• Adjust Pages — Preview, rotate, duplicate and delete pages, insert blank pages, then export
• Split PDF — Split per page / by range, or manually in page mode
• Extract Pages — Pick pages in page mode then extract as a new PDF
• Rotate PDF — Rotate selected pages by 90/180/270 degrees
• Reverse Pages — Flip the page order of a PDF end to end
• Split Pages in Half — Cut every page into 2 halves or a 2×2 / 3×3 grid
• N-up PDF — Place 2/4/6/9/16 pages on one sheet for printing
• Grid Combine — Arrange pages from multiple PDFs on a grid sheet
• Remove Blank Pages — Detect blank pages by pixel entropy, review and delete