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PDF Tools · Updated October 20, 2026

Add a Watermark to a PDF

You can add a text watermark to every page of a PDF in your browser: choose the wording, size, opacity, angle and layout, then download a watermarked copy without uploading the document.

Runs in your browserFree · No sign-up · No watermark
PDFRuns in your browser
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Everything runs locally in this tab. No file is uploaded while the tool loads.

This tool runs in your tab. Nothing is uploaded and no copy is stored.

How files are handled

At a glance

Formats
PDF → PDF
Processing
In your browser
Max size
Up to 100 MB
Price
Free, no account
Updated
October 20, 2026
All PDF Tools

About Watermark PDF

A watermark marks a draft, an internal copy or a document that should not be reused without permission, but most PDF editors keep the feature behind a subscription. Rebuilding the page as an image just to add a label is worse: the text stops being selectable and the file usually grows.

This tool stamps one line of text directly onto every page with pdf-lib, using the font size, opacity, angle and layout you choose. Place a single diagonal mark in the middle, repeat it as a tiled pattern across the page, or set a short horizontal line in the footer. The rest of the page is untouched, so existing text stays selectable and the original file is never modified.

What this tool does

The details that matter when you use Watermark PDF for real work.

  • One mark or a full pattern

    Choose a single centered watermark, a tiled pattern that repeats across the page, or a short horizontal line in the footer.

  • Size, opacity and angle

    Set the font size from 24 to 96 points, dial the opacity down so the page stays readable, and rotate the mark to 0, 45 or 90 degrees.

  • Every page in one pass

    The same watermark is applied to all pages, so a twenty-page contract takes one click rather than twenty.

  • Text stays selectable

    The watermark is drawn over the existing page content instead of flattening it, so the document's own text is still searchable and copyable.

  • A new file, not an edit

    The original PDF is only read. The download is a separate copy named after the source file with -watermarked.pdf added.

  • Runs in your browser

    The PDF is read, stamped and saved locally with pdf-lib. Nothing is uploaded and no queue is involved.

How to use Watermark PDF

No account, no installation — the whole job happens in this browser tab.
  1. 01

    Add the PDF

    Drop one PDF into the workspace. Its page count is read locally so you can see exactly what will be stamped.

  2. 02

    Write the watermark text

    Type the wording you need, such as CONFIDENTIAL, DRAFT or the name of your organization. One line is enough.

  3. 03

    Pick the layout

    Choose a centered mark, a tiled pattern or a footer line, then set the font size, opacity and angle.

  4. 04

    Apply the watermark

    Click Add watermark. Every page is stamped in the browser and the progress bar tracks the pages.

  5. 05

    Download the copy

    Preview the first page, then download the new PDF. The original file is left unchanged.

Supported formats and limits

Input
PDF
Output
PDF
Processing
Client-side, in your browser. Nothing is uploaded.
Maximum size
Up to 100 MB
Requirements
Chrome, Edge, Firefox or Safari

Limitations worth knowing

  • Text watermarks only — there is no image, logo or stamp artwork option.
  • Watermark text is limited to characters the built-in Helvetica font can encode: Latin letters, digits and common punctuation.
  • Every page gets the same mark; per-page wording and per-page placement are not supported.
  • The watermark is drawn into the page content, so it cannot be toggled off or moved later without a PDF editor.

Privacy and file handling

The PDF is opened, watermarked and saved entirely inside your browser tab with pdf-lib. The file is never uploaded, no copy is stored on a server, and the original document is not modified. Closing the tab discards everything.

Read the full privacy policy

Watermark PDF FAQ

Short, direct answers to the questions people ask before using this tool.
Can I add an image or logo watermark instead of text?
No. This tool stamps text only, so a company logo, signature or stamp artwork needs a different workflow. Export the logo as an image and place it with a PDF editor that supports image watermarks.
Does a watermark stop people from copying the content?
No. A watermark is a visible label, not security. Anyone with a PDF editor can remove or cover the mark, and text can still be extracted. Use password protection or access controls if you need to restrict reading.
Why does my watermark show up as blank boxes?
The built-in PDF font only covers Latin characters and common punctuation, so Chinese, Arabic, Cyrillic and emoji cannot be embedded. Rewrite the watermark in Latin letters, or use a PDF editor that can embed a font you supply.
Can I watermark only some pages of the document?
Not in this tool: every page receives the same watermark. To mark part of a document, split the PDF first, watermark the section you need, then merge the parts back together in the right order.
Does adding a watermark make the PDF bigger?
Only slightly. Each page gains a short text command and a transparency setting, so a typical file grows by a few kilobytes. Existing text, images and fonts are not re-rendered or recompressed.
What happens if the PDF already has a watermark?
The new mark is drawn on top of whatever is already there, so the old watermark shows through underneath. Nothing is erased. Start from an unmarked copy if you need to replace an existing mark cleanly.
Can I move or remove the watermark later?
The mark becomes part of the page content, so moving or deleting it needs a PDF editor that can edit content streams. It is not a separate layer that a viewer can switch off. Keep the original if you may need a clean version.
Does this tool work with password-protected PDFs?
No. Encrypted documents cannot be opened for editing without the password, so the tool stops with a clear message. Save an unprotected copy first, then watermark that copy.

Background reading

Format guides that explain the trade-offs behind Watermark PDF.