Watermark PDF (text)

Opacity here is a genuine transparency value written into the PDF, not a lighter shade of the chosen colour, so page content shows through the stamp instead of being covered by it. The slider runs from 10 to 100 per cent and starts at 30, which is usually the sweet spot — clearly legible on screen and in print without fighting the body text. At the low end a pale stamp can wash out over a busy scan; at 100 per cent it is solid and will obscure whatever sits beneath it. Because nothing underneath is deleted, the page's own text stays selectable and searchable exactly as before. Step through several pages in the preview before downloading, since a value that works over plain text can read very differently over a dark photograph.

Rotation and position are two separate settings that combine. Rotation offers 0°, 45°, -45° and 90°, defaulting to -45° — the classic corner-to-corner slant. Position offers Center, Diagonal and Bottom right: Center and Diagonal both place the stamp in the middle of the sheet, while Bottom right tucks it into the corner with a 36-point margin. One special case is handled for you: Diagonal combined with 0° would be a contradiction, so the tool substitutes 45°. Rotation happens around the stamp's own visual centre, which is why changing the angle does not shove the text off the page. On pages carrying their own rotation flag the stamp is turned to match, so a landscape page reads the same way round as a portrait one.

Tiling is not offered — each run draws exactly one line of text per page, at one position. To make the stamp reach across the whole sheet, raise the font size, which goes all the way to 400 points, and leave Position on Diagonal so the words run corner to corner. To get two marks on the same page, run the tool twice: stamp the file once with Diagonal, then drop the downloaded result back in and stamp it again with Bottom right. Each pass writes into the page's content stream, so the second mark lands on top of the first without disturbing it. Multi-line watermark text is not supported either — the stamp is a single line, so a long phrase is better shortened than wrapped.

A text watermark from this tool is drawn into each page's content stream, so there is no annotation layer to switch off and no viewer setting that hides it — every reader and every printer shows it. That is not the same as tamper-proof. Anyone with a full PDF editor can select the drawn text and delete it, and there is no cryptographic link between the stamp and the document. Treat it as visible labelling — marking a draft, tagging a sample, naming a recipient — not as protection. If you need to restrict what someone can do with the file, encrypt it with Add password to PDF; if content must be taken out rather than covered, Redact PDF in Wipe mode is the right tool. Keep an unstamped master, because this tool cannot undo its own watermark.

No — watermarking happens entirely inside the browser tab, with no upload at any stage. Marking something CONFIDENTIAL by first uploading it to a stranger's server would be a strange way to go about it, and this tool never does: the PDF is read from disk by the browser, the stamp is drawn locally page by page, and the result is written to your downloads as a -watermark file. The words you type in the Watermark text box are just as local — a client name or a case reference typed there goes into the PDF and nowhere else. Nothing is logged, queued or retained, and once the page has loaded the tool keeps working with the network disconnected. Watch the Network tab in DevTools if you want to see it for yourself.

It is free, and no — the only watermark on the output is the one you configured. That is worth stating plainly on this page in particular, because free watermarking sites are the classic place to discover a second, uninvited stamp advertising the site itself. PDFChamp adds none of it: no logo, no corner credit, no metadata line, and there is no paid tier where branding conveniently disappears. Every control on the card — the full 6-to-400-point size range, the custom hex colour, all four rotation presets and all three positions — works on the first run without an account. Documents of any length are accepted; a long one simply takes a little longer, because each page is drawn separately.