Watermark PDF

Stamp diagonal text — CONFIDENTIAL, DRAFT, PAID, your brand — across every page, with adjustable opacity.

What is the Watermark PDF tool?

The Watermark tool stamps diagonal text across every page of a PDF — CONFIDENTIAL, DRAFT, SAMPLE, PAID, a client name or your brand. You control the wording and the opacity, so the mark can be a whisper in the background or an unmissable banner. It’s the standard way to label document status and discourage unauthorized reuse before you share a file.

Key features

  • Any custom text — status labels, names, dates, brands
  • Opacity control from 5% (subtle) to 100% (bold)
  • Classic 35° diagonal placement across the page
  • Text auto-sizes to the page so long phrases still fit
  • Applied to every page in one pass, on your device

How do I use it?

  1. Drop the PDF you want to mark.
  2. Type the watermark text (default: CONFIDENTIAL) and set opacity.
  3. Click Apply & download.
  4. Every page of the downloaded copy carries the diagonal watermark.

Is it safe to watermark a PDF online?

Yes. The watermark text is drawn into each page locally, in your browser — the document is never uploaded. Note that a visible watermark is a deterrent and a status label, not encryption: someone determined can still read the underlying content, so for secrecy also control who receives the file.

Tips for the best result

  • 15–25% opacity marks a page clearly without hurting readability.
  • Use dates in the text (e.g. “DRAFT — July 2026”) for version control.
  • Watermark the copy you send, keep your clean original.
  • For photos-as-PDF, a slightly higher opacity (30–40%) reads better.

Frequently asked questions

What text can I use as a watermark?

Anything — CONFIDENTIAL, DRAFT, SAMPLE, PAID, a client’s name, your company, a date. The text auto-scales to fit the page diagonally.

Can I control how strong the watermark looks?

Yes — set opacity from 5% to 100%. Around 20% is visible but keeps the document easy to read.

Is the watermark applied to all pages?

Yes, every page gets the same diagonal stamp in one pass.

Can a watermark be removed later?

A visible watermark deters casual reuse but is not tamper-proof; treat it as labeling, not security.

Will watermarking blur my document?

No — the mark is a crisp text layer drawn over the page; the underlying content is unchanged.

Is my file uploaded to watermark it?

No. Everything happens in your browser and the PDF never leaves your device.

Related tools: Page Numbers · Compress PDF · Merge PDF

Also searched as: add watermark to pdf free, confidential stamp pdf, draft watermark online.

🔒 Privacy: this tool runs entirely in your browser. Your file is never uploaded, stored, or shared. LyfPDF offers 22 free PDF tools, including 17 localized tools in 7 languages, with 0 uploads — learn how it works.

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