How to add a watermark to a PDF
Last updated: September 5, 2026
A DRAFT stamp stops a half-finished document being mistaken for the final version; CONFIDENTIAL makes the handling expectation explicit. Here's how to stamp a text watermark across a PDF, free, and without uploading the file.
Use our free Add Watermark to PDF tool. It runs in your browser.
Stamping a watermark in five steps
- Open the Add Watermark tool.
- Select or drag in your PDF.
- Type the watermark text:
DRAFT,CONFIDENTIAL, a date, a recipient's name. - Choose the layout, then set the opacity and font size so the mark reads without swallowing the page.
- Click Add watermark and download the marked PDF.
Tiled or single: matching the mark to the message
- Single, centered: one clear stamp per page. Right for
PAID,COPYor a version label, where you want an unmistakable note but the document must stay easy to read. - Tiled diagonal: the text repeats across the whole sheet at an angle. The standard choice for
DRAFTandCONFIDENTIAL, because the status stays visible in any crop, screenshot or partial photocopy, and no clean-looking region survives to be passed off as a final page.
Getting opacity and size right
The two dials that decide whether a watermark helps or hurts are opacity and font size. Opacity runs from a faint 5% to a bold 80%. The trap is going too strong: a heavy, near-opaque stamp fights the body text and makes the document tiring to read, which defeats the point of sending it at all. As a rule of thumb, a tiled background sits comfortably low, and a single centered stamp can afford to be a little bolder because it only touches part of the page.
| Layout | Suggested opacity | Reads as |
|---|---|---|
| Tiled diagonal, background | 10–20% | A clear status wash you can still read straight through |
| Single centered stamp | 25–40% | A firm PAID / COPY mark that leaves the text legible |
| Bold statement | 50–80% | Impossible to miss, but only where readability is secondary |
How the stamp is applied
Under the hood the watermark is text drawn onto every page (semi- transparent and, in tiled mode, rotated to run diagonally) over the top of the existing content. It is not a separate note or comment floating in an annotation layer; it is written into each page so it appears in every reader and on every printout. That is what makes it a dependable label rather than something a viewer can simply switch off.
What a watermark does, and what it doesn't
Be clear about the limits: a watermark is a signal, not security. Anyone with a capable PDF editor can crop it, paint over it, or rebuild the page, and determined removal is always possible. For genuine confidentiality you need encryption, or the old discipline of sharing a marked copy while keeping the clean original close. What a watermark reliably delivers is the removal of any excuse: nobody can claim they "didn't realise" a document was a draft or was not meant to be forwarded when the word is stamped across every page.
Watermark last, share immediately after
Stamp the copy you send, never the master you keep. The sensible order is to finish the content first, merge or trim pages, add page numbers, and only then watermark, because a watermark applied before you rearrange pages can end up mismatched, and there is no clean way to peel it back off.
Applied privately, on your device
There is a neat irony in uploading a document to a stranger's server precisely because it is confidential, so this tool doesn't. The watermark is drawn in your browser and the file never leaves your machine, which is exactly the guarantee you want at the moment you are marking something sensitive. The mechanics of why that is possible are covered in are online PDF tools safe.
Frequently asked questions
Can I remove the watermark later? Not from within this tool; it is drawn into each page. Keep your unmarked original; re-stamp a fresh copy whenever you need a different mark.
Does the watermark print? Yes. It is part of the page content, so it appears on paper and in every PDF reader, not just on screen.
Will it cover up my text? Only as much as you allow. A low opacity leaves the body text fully readable; that is why the tool lets you tune it from 5% up to 80%.
Can I use an image or logo as the watermark? This tool stamps text. To place a logo or seal on the pages, use Add Image instead.
Is a watermark enough to keep a document private? No. It is a visible label, not encryption. Treat it as a deterrent and a status marker, and keep genuinely sensitive originals unshared.