Add Watermark to PDF Free - Text Overlay
Add a text watermark to every page of a PDF. Type your text (e.g., "CONFIDENTIAL," "DRAFT," your company name), choose the color, size, opacity and angle, and save. The watermark is stamped on every page without altering the original content. Everything runs in your browser, so the PDF is never uploaded. Perfect for marking documents as drafts, confidential, or for branding purposes. No sign-up, no watermark from us, no limits.
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When to use it
Mark a review copy as DRAFT
Type DRAFT in “Watermark text”, keep “Opacity” near 25% and “Angle” at -45° to get a diagonal mark that does not hide the content. Press “Save PDF” and the file downloads as name-watermark.pdf.
Stamp CONFIDENTIAL on a document you send out
Pick a red tone, raise “Opacity” to around 40% and enlarge “Size” until the word spans the page. Longer text needs a smaller size so it stays within the page.
Put a company name straight across the page
Set “Angle” to 0° for a horizontal line. A light gray at low opacity identifies the source without covering the body text.
How to use
- Drop a PDF into the box or click to choose one.
- Type your watermark text and adjust color, size, opacity and rotation angle.
- Press Save PDF to download the watermarked version.
How it works
Your PDF is loaded by pdf-lib in your browser. The watermark text is drawn on each page as a transparent text overlay at the position, angle, size, color and opacity you choose. The original page content is untouched underneath. Because pdf-lib manipulates the PDF structure directly in JavaScript, the entire process is client-side and the file never leaves your device. How to verify. Also available as a free REST API for developers and AI agents (edge-processed, zero retention).
Also available as: Sign PDF | Add Page Numbers
FAQ
Can I customize the watermark text?
Yes. Type any text you want. Common watermarks include "CONFIDENTIAL," "DRAFT," "DO NOT COPY," or a company name.
Can I adjust the opacity?
Yes. Use the opacity slider to make the watermark more or less visible. Around 20-30% opacity is common for background watermarks.
Does the watermark appear on every page?
Yes. The watermark is added to all pages of the PDF. Page selection may be added in the future.
Is my PDF uploaded?
No. Everything runs in your browser using pdf-lib. The file never leaves your device.
Can I remove a watermark?
This tool adds watermarks. Removing watermarks from existing PDFs requires editing the PDF content, which is not supported by this tool.
Can I use an image or logo as the watermark?
No. Only a text watermark is supported.
Can I stamp only some pages or tile the text across the page?
No. The text is placed once, centered on every page. There is no page selection and no repeated pattern.
Does non-English text work?
Yes for Korean. When the text contains characters beyond plain Latin letters and numbers, the NanumGothic font is loaded and embedded, so the first save can take a little longer. Characters that this font does not contain, such as other scripts, may not display correctly.
Does the watermark sit above or below the page content?
Above. It is drawn on top of the page, so use a lower opacity or a light color if the text underneath must stay readable. Placing it behind the content is not supported. Non-English text such as Korean is saved with an embedded Nanum Gothic font.
Can I choose where the watermark goes on the page?
It is always centered on the page. Change "Size" and "Angle" to make a large diagonal mark. Placing it in a corner or dragging it to a custom spot is not supported.
Last checked: October 10, 2026 · Dagochim team