How to add a watermark to a PDF

How to add the watermark step by step

Adding a watermark to a PDF takes under a minute, from the original file to the watermarked PDF, without leaving the browser:

1. Open the Watermark tool.
2. Upload the document you want to mark. It stays on your computer.
3. Type the watermark text, for example, CONFIDENTIAL, DRAFT or your company name, and press apply.
4. Download the watermarked PDF, ready to share.

Nothing to install, no account and no upload wait. The text is stamped diagonally across every page of the document at once, and the result appears instantly.

Tips for a watermark done well

• Keep the text short. The font shrinks as the text grows, but only down to a minimum of 24 points; past that point it stops shrinking and the watermark can spill past the page width. One or a few words always give the best result.
• If you leave the field empty, the text is CONFIDENTIAL. The tool automatically uses the word "CONFIDENTIAL" as the watermark; you cannot apply a watermark with no text at all. If you want a different word or phrase, type it in the field before applying, because there is no way to change it after the file downloads.
• If the PDF already carries a watermark, this one stays underneath. This tool only adds the new one on top; it does not detect or erase any watermark already on the document.
• The mark appears on every page, no exceptions. There is no way to choose only some sheets; if that is what you need, look at the Overlay PDF tool instead.
• It works offline. Once the page has loaded once, you can watermark PDFs with the network off, the work is all done by your processor.

What this tool does and what it does not do

The Watermark tool stamps text diagonally across every page of a PDF. That is what it does, and it helps to know where the limits are:

• It only accepts text. You cannot upload a logo or an image. If you need an image-based mark, one alternative is to draw the first page of a PDF (with your logo) on top of every page of another, with the Overlay PDF tool.
• The style is fixed. Light grey, about 28% opacity, always diagonal. Only the text itself is yours to choose.
• It does not remove existing watermarks. If what you need is to take out a mark that is already there, this is not the right tool: the file would need to be worked on at its source.
• It stamps the whole document. The text is applied to every page at once, with no way to choose only some.

If what you want is a final touch of authenticity, you can pair the watermark with a signature: the Sign PDF tool lets you draw, type or upload your signature without printing anything. You can also finish the document with page numbers, using the Number pages tool.

Is adding a watermark free? What are the limits?

No. This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.

Sources

• BestPDFInTheWorld, Marca de água
• MDN, File API
• pdf-lib