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How to add a watermark to a PDF in your browser

Stamp DRAFT, CONFIDENTIAL, or any short text across every page of a PDF with a diagonal or tiled layout, entirely on your device.

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Stamp DRAFT, CONFIDENTIAL, or any short text across every page of a PDF — entirely in your browser, no account needed.

Before you start

  • The Watermark tool is free and runs 100% locally. Your PDF never leaves your device — the stamping happens in the browser, and you can watch the network tab in DevTools to confirm nothing is uploaded.
  • Watermark text is capped at 60 characters, and runs of whitespace are collapsed to single spaces.
  • Many government forms (USCIS, IRS) ship "permission-encrypted" with an empty password. The tool unlocks these automatically on your device when you load them — you'll see a note that the PDF was unlocked and nothing was uploaded. A PDF locked with a real password can't be opened here; see the troubleshooting guide.

Steps

  1. Open the Watermark tool.
  2. Drag your PDF onto the drop zone, or click it to choose a file.
  3. Type your text in the Watermark text field. It's prefilled with CONFIDENTIAL — replace it with anything up to 60 characters, like DRAFT, SAMPLE, or DO NOT COPY.
  4. Pick a layout — Diagonal or Tiled — and a color — Gray, Red, or Blue (see the table below).
  5. Click Apply watermark. The button reads "Applying…" while the mark is drawn on every page.
  6. Check the preview. It renders page 1 of the result and shows the total page count ("Preview · page 1 of 12").
  7. Tweak if needed. Changing the text, layout, or color after applying dims the preview and shows "Settings changed — apply to refresh"; click Update watermark to re-stamp. Updates always re-stamp your original file, so you never get doubled-up marks.
  8. Click Download watermarked PDF. The file saves as yourfile-watermarked.pdf; your original file is untouched.

Layouts and colors

OptionWhat it does
DiagonalOne large 45° mark across the center of every page — the classic DRAFT/CONFIDENTIAL look, auto-sized to span the page.
TiledThe text repeated in a faint diagonal grid over the whole page — full coverage that's harder to crop out.
Gray / Red / BlueThe ink color. Marks are drawn semi-transparent (tiled slightly fainter than diagonal) so the page underneath stays readable.

Result

Every page of the downloaded PDF carries the watermark, baked into the page content itself — not a removable annotation that a viewer can simply toggle off. Non-Latin text works too: Cyrillic, Greek, Vietnamese, and other scripts are stamped with an embedded Unicode font, and any character even that font can't cover becomes ? instead of failing.

Two honest notes:

  • A watermark is a visible deterrent, not security. A determined recipient can rebuild a page without it. To actually remove sensitive content, use Redact; to require a password to open the file, use Protect.
  • Unlike most online watermark tools, your PDF is never round-tripped through a server here — the privacy promise is the whole point of doing it in the browser.

Need to sign the watermarked file? After applying, the tool offers a Sign this PDF link straight into Sign.

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