Stamp a diagonal text watermark across every page of a PDF, on your device.
Watermarked PDF ready.
This tool opens your PDF with the pdf-lib library and draws your chosen text diagonally across the centre of every page, then saves a new copy. Because it adds the watermark as a semi-transparent text layer rather than re-rendering the pages, the original content stays crisp and selectable underneath. Everything happens in your browser, so the document — often a draft or a confidential file — is never uploaded to a server.
Type any label you need, such as Confidential, Draft, Sample or your company name. The size options control how boldly the text spans the page, while the opacity setting balances visibility against readability — a lower opacity keeps the underlying text easy to read, a higher one makes the mark harder to ignore or remove. Grey suits most documents, while red or blue stand out more for warnings or branding. The same watermark is applied consistently to every page.
Watermarking is useful for marking a document as a draft before it's final, flagging sensitive files as confidential, labelling sample or preview copies, or lightly branding a PDF you share. Since the watermark is part of the page content in the exported file, it stays in place when the PDF is viewed, printed or shared — while your original file remains untouched on your device.
It's drawn into the page content, so it can't be toggled off by a normal reader. Dedicated editing tools could still remove it, so it deters rather than permanently locks.
Yes, the same watermark is applied to all pages of the document in one pass.
Yes. The watermark is an added layer; the original text and images remain intact and selectable beneath it.