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Stamp a diagonal line of text across every page of a PDF — like CONFIDENTIAL, DRAFT or your company name. The watermark is applied inside your browser, so the file is never sent to a server.
Drag your files here
or click to select
Add the PDF
Drag the file onto the upload area or click to pick it. The document is read only in your device's memory.
Type the text
Enter the watermark text (for example, CONFIDENTIAL). It is drawn diagonally across the center of every page.
Download the result
Click apply and download the watermarked PDF. No copy of the file is kept anywhere.
A watermark instantly signals the status or origin of a document without anyone having to read the content. Stamping DRAFT keeps a preliminary version from being mistaken for the final one; CONFIDENTIAL makes clear that the material should not circulate; and a company name or logo reinforces the authorship of proposals and reports.
It also helps discourage misuse. A document with a visible diagonal mark is harder to repurpose as someone else's own, which protects contracts, quotes and original material when they have to be shared.
Many online watermark tools upload your PDF to a server, apply the text there and send the result back. For a confidential document — exactly the kind that most often gets a watermark — that means handing the content to a machine you don't control.
On Free PDF Lover, the watermark is applied entirely in the browser. The PDF is read in your device's memory, stamped right there and handed back for download without ever leaving for the internet. That's the sensible default for a file you're marking as private.
The text you choose is drawn diagonally (45°), centered on each page, in a semi-transparent gray. The transparency matters: the mark stays visible but doesn't hide the content, so the document remains perfectly readable.
The mark is stamped over the pages without recreating them, preserving the original text and images. The stamp size adapts to each page's dimensions, so it stays proportional on A4 sheets as well as on larger or landscape pages.
Even a PDF with many pages gets watermarked without locking up the interface. Processing runs in the background, in a Web Worker separate from the screen, so the page stays responsive and you can follow the progress while the stamp is applied.
Because everything happens on your device, performance depends on available memory rather than on a server. On a computer, long documents are marked in seconds; on an older phone, very large files may take a little longer, but nothing is sent off the device.
Yes. The tool is free and needs no sign-up for basic use.
No. The watermark is applied entirely inside your browser. The PDF is never transmitted to the internet or stored.
Yes. You type any text you want (such as CONFIDENTIAL, DRAFT or your company name), and it is applied to every page.
No. The text is semi-transparent and sits in the background, diagonally, so the content stays readable.
Yes. The text is centered and applied to each page of the document, with the size adjusted to the page.
No. The mark is drawn over the pages without recreating them. The original text and images stay intact.
Yes. The tool works on phones and tablets; only very large files may need more memory on older devices.
No. Everything runs in the browser, with nothing to install and no extensions.