Watermark PDF

Upload a PDF and the tool adds a text watermark - 'DRAFT', 'CONFIDENTIAL', 'SAMPLE', or anything else you type - on every page of the document. You control text size (defaults to 48pt for diagonal centred watermarks, looks right on most A4 pages), opacity (the default 40% is faint enough to read the underlying document but obvious enough to be noticed), rotation (45 degrees diagonal is standard; 0 degrees gives horizontal text), and colour (grey, red, or blue - red is the conventional choice for 'DRAFT' or 'CONFIDENTIAL' to draw attention).

Position has two main modes: centre, which puts a single large watermark in the middle of each page, and tiled, which repeats the watermark across the entire page in a grid pattern. Centre is the right choice for legal documents and standard 'this is a draft' marking; tiled makes the document much harder to photograph or screenshot without the watermark visible, which is what you want for 'CONFIDENTIAL' content circulated to people who shouldn't share it.

Draft contracts and proposals: 'DRAFT' watermark prevents anyone from accidentally treating an unsigned proposal as final. Send the unwatermarked clean version only when the client agrees the contents are settled. Confidential business documents: 'CONFIDENTIAL' watermark on financial reports, board papers, or strategy documents is a visual reminder that the recipient shouldn't forward or share the file. It doesn't enforce anything technically, but it removes plausible deniability if someone shares it anyway.

Sample work for portfolios or pre-purchase preview: photographers, designers, and writers commonly watermark sample work with their name or 'PREVIEW' to deter unauthorised use before payment. The tiled pattern is most effective here because it's much harder for someone to crop or remove. For sensitive personal documents (bank statements, medical records) being sent to a third party for a specific purpose, watermarking with the recipient's name or 'For [Purpose] Only' creates an audit trail discouraging misuse. To genuinely lock down access (rather than discourage misuse), use the [protect PDF](/protect-pdf) tool to add a password instead.

A determined recipient with image editing software can remove a watermark from a flat-rendered PDF page given enough time, especially low-opacity ones. The watermark is a deterrent, not a lock. For genuinely confidential information you don't want people sharing, combine watermarking with PDF password protection (so they can't open it without the password) and access controls (so you control who has the password). The [protect PDF](/protect-pdf) tool handles password protection.

What watermarks do well: flag the document's status (draft, confidential, sample) so anyone glancing at any page can see immediately. Make screenshots and photos of the document obviously watermarked, which makes social media leaks self-incriminating. Add a paper trail (especially with named-recipient watermarks) so you know which copy leaked if multiple copies exist. They don't prevent removal by a skilled adversary, but they raise the friction of casual misuse from zero to non-trivial.

The watermarking happens entirely in your browser using pdf-lib. Your PDF never uploads to any server, never gets stored, never gets logged. Once you close the tab, the only copies are the original on your device and the watermarked version you downloaded. This is the right architecture for confidential documents - the worst version of this tool would upload your contract draft to a server in another country, watermark it there, and email back a link.

Performance is good for most documents under 100MB. Very large PDFs (200+ pages with embedded images) can take 10-30 seconds to process and may strain phone browsers. If a watermark stalls, try a smaller font size or move from tiled to centre mode (tiled adds many text instances per page and is heavier than a single centred watermark).