Aller au contenu
Retour à tous les outils№ 069

Superposer un PDF

Superpose un PDF de tampon, de papier en-tête ou de filigrane au-dessus ou en dessous des pages d’un autre PDF.

Chargement de l’outil…

An overlay puts one PDF onto another. Which one ends up on top is the whole question, and it decides what the operation is for. Above the content is a stamp — an APPROVED mark, a draft notice, a logo that must be visible over the text. Below the content is a letterhead: your headed paper sits behind a plain document, exactly as if the pages had been printed onto pre-printed stock.

The overlay is scaled proportionally to fit each base page and centred, so a differently-sized stamp does not need preparing first. If the overlay has fewer pages than the base, its last page repeats by default; tick the loop option and its pages cycle in order instead, which is what you want for alternating left and right letterheads. You can apply it to every page, the first page only, or a range.

How it works

  1. Add the base PDF and the overlay PDF.
  2. Choose above the content for a stamp, or below it for a letterhead.
  3. Set the scope: all pages, first page only, or a range.
  4. Decide whether a short overlay repeats its last page or loops, then apply.

What people use it for

  • Putting company letterhead behind a document generated by a system that cannot do it.
  • Stamping DRAFT or CONFIDENTIAL across a document from a prepared stamp PDF.
  • Adding a printed frame or a border to every page of a certificate run.

Frequently asked questions

Is my file uploaded to a server?
No. The file is opened by JavaScript and WebAssembly running inside your own browser tab. It is never uploaded, there is no server-side processing and nothing is stored — closing the tab discards everything.
Should the overlay go above or below?
Above for anything that must be seen over the text, such as a stamp or a watermark that should not be missed. Below for letterhead and backgrounds, so the document's own text stays fully legible on top of it.
My overlay is a different page size.
That is handled: it is scaled proportionally to fit each base page and centred, so it is not distorted. If the proportions are very different you will see it sitting inside the page rather than filling it.
What happens when the overlay has fewer pages than the base?
Its last page repeats for the remainder — normally what you want with a single-page stamp. Tick the loop option to cycle its pages in order instead, which is how you alternate two letterhead designs across a document.
How is this different from the Watermark tool?
Watermark generates a mark from text or an image you supply. Overlay uses a PDF you already have, so a designed stamp or an official letterhead keeps its exact typography and vector quality.

Outils similaires