Our new Add Watermark to PDF tool stamps a text watermark across every page of a PDF using pdf-lib, running entirely in your browser — no server, no upload, no account.
- Your own text — the default is “CONFIDENTIAL”, but the field is editable, so “DRAFT”, a company name, or anything else works just as well.
- Full control over size, opacity, and angle — a font-size slider, an opacity slider from barely-there to solid, and a rotation angle in degrees (45° by default, for the classic diagonal watermark look).
- Instant re-generation, never stacked — every change re-derives the watermark from your original, untouched file, so adjusting a slider ten times never layers ten overlapping watermarks on top of each other.
- Burned in, not a removable layer — pdf-lib draws the watermark as real vector text merged into each page’s own content, the same way a printed stamp would be permanent — meaningfully different from an overlay you could just delete.
- Private by default — your PDF is read locally and processed in your browser tab; nothing is ever sent to a server, which matters most for exactly the kind of sensitive drafts and contracts people watermark.
Choose a PDF, tune the text and look to taste, and download — the whole thing happens without your file ever leaving your device.