Stamp PDFs
Lay one document over or under another.
This tool runs entirely in your browser. Your file is never uploaded, and you can verify that in your browser's network tab. Verify it yourself: open your browser's network tab and watch. You will see one small request asking whether you have tasks left - a tool name and a hash, never the file.
What this does
This draws every page of one document onto the corresponding page of another. Unlike merging, which puts documents next to each other, this puts them on top of each other.
Use it to apply a letterhead or a branded background to a plain document, to stamp a DRAFT or CONFIDENTIAL overlay that you designed elsewhere, or to place content onto a pre-designed form so it prints as one piece.
How it works
- Drop both PDFs onto this page.
- Say which of the two is the stamp - by default it is the second one.
- Choose whether the stamp goes over the content or behind it. A letterhead usually goes behind; a DRAFT mark goes over.
- Set the fit and the opacity, then press Stamp.
- The download starts immediately.
Over and behind work differently under the surface, and the difference costs something worth knowing about. Drawing over adds to the existing page, so links, form fields and annotations on the base document survive. Drawing behind cannot be done that way - a PDF content stream can only be appended to - so the result is composed onto fresh pages instead, and the base document's annotations do not carry across. If your document has fillable fields you want to keep, stamp over rather than behind.
When the stamp has fewer pages than the base, repeat decides what happens. Repeat the last page suits a letterhead whose second page differs from its first. Cycle suits an alternating left-right design. Stop leaves later pages unstamped.
Fit controls scaling. Contain keeps the stamp's proportions and centres it, which is right for a logo. Stretch fills the page exactly, which is right for a full-page background designed at a different size. None places it at its original size.
Opacity below one is how you turn a solid design into a background that text stays readable over. For a plain text or diagonal watermark, Add watermark is a more direct tool than building a stamp file first.
What this tool cannot do
- Stamping behind composes onto new pages, so links, form fields and annotations on the base document are not carried over. Stamping over keeps them.
Questions people ask
- What is the difference between over and behind?
- Over draws the stamp on top of the existing content and keeps the base document's links, form fields and annotations. Behind places the stamp underneath, which requires rebuilding the pages, so those annotations are lost. Use over if the base document has fillable fields.
- My stamp has one page and my document has fifty. What happens?
- By default the last stamp page is repeated across all remaining pages, so a one-page letterhead lands on every page. You can switch to cycling through the stamp, or to stopping once the stamp runs out.
- The two documents are different page sizes. Will it line up?
- With fit set to contain the stamp is scaled to fit and centred, keeping its proportions. Stretch makes it match the page exactly, which distorts it if the aspect ratios differ. None places it at its original size from the centre.
- Should I use this to add a watermark?
- Only if you already have the watermark as a PDF. For plain text or a diagonal stamp, Add watermark is more direct - it generates the mark for you rather than making you build a file first.