Watermark PDF
Stamp text like CONFIDENTIAL, DRAFT or your name across every page of a PDF — without installing anything or uploading the file. You control the wording, color, opacity, rotation, font size and position, and a live preview of the first page shows the result as you adjust. Processing runs entirely in your browser, so the document never leaves your device.
100% in your browser. Your file never leaves your device.
Features
- Free-form watermark text with adjustable color, opacity, rotation, font size and position.
- Live preview on the first page updates instantly as you change settings.
- The watermark is applied to every page of the document in one pass.
- All processing happens locally with pdf-lib — your PDF is never uploaded.
- Original page content, text and vector graphics stay untouched underneath the stamp.
- The result downloads as a new file with a -watermarked suffix in the name.
About this tool
When you drop a PDF onto the page, the tool opens it entirely on your machine. PDF.js renders the first page as a small preview so you can judge the result before committing. Your watermark settings sit on top of this preview as a live overlay: every change to text, color, opacity, rotation, size or position repaints it immediately.
When you click Apply watermark, pdf-lib takes over. It loads the original file into memory, embeds the standard Helvetica Bold font, converts your chosen color into PDF color values and writes the text onto each page at the selected position, angle and opacity. The existing page content is neither re-rendered nor rasterized — the stamp is simply drawn on top.
Both libraries run as JavaScript inside your browser tab. The PDF is read from your device, modified in memory and handed back through the normal save dialog — no server ever receives the file. That makes the tool a reasonable choice for confidential contracts or unpublished drafts. When you close the tab, the file and all settings are gone.
How to add a watermark
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Select your PDF
Drag the PDF onto the drop zone or click to browse for it. The tool reads the file locally and renders the first page as a preview — nothing is transferred to a server.
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Enter the watermark text
Type the wording you want, for example CONFIDENTIAL, DRAFT or a copyright line. The default is CONFIDENTIAL; the stamp on the preview updates while you are still typing.
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Adjust style and position
Pick a color, set the opacity between 10 and 100 percent, rotate the text from -90 to +90 degrees, choose a font size from 10 to 200 points, and select center, top, bottom, left or right.
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Check the live preview
The first page shows the stamp as configured. Fine-tune until it is readable but not obtrusive — around 30 percent opacity and a slight diagonal angle work well for most documents.
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Apply and download
Click Apply watermark. pdf-lib writes the text onto every page and your browser offers the result as a new file ending in -watermarked.pdf. Your original file stays untouched.
Typical use cases
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Marking drafts and internal versions
Before circulating a report or contract for review, stamp DRAFT diagonally across every page. Anyone who prints or forwards the file immediately sees it is not the final version, so outdated copies don't get treated as approved. Because everything runs locally, even sensitive pre-release documents can be marked without uploading them anywhere.
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Protecting quotes and portfolios
Freelancers and agencies often send concept papers, quotes or design portfolios that shouldn't be passed along unmarked. A semi-transparent watermark with your name or company on every page makes quiet reuse unattractive while leaving the content perfectly readable. Keep the opacity low so the work still looks presentable to the actual client.
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Labeling confidential documents
HR paperwork, financial statements or legal correspondence often need a visible CONFIDENTIAL notice before being shared internally. The tool applies the label to every page in one pass, so nothing slips through on page 14 of a long document. The red default color and centered position match the classic confidentiality stamp, and both can be changed freely.
Tips & limitations
- The watermark uses the built-in Helvetica Bold font, which only supports Western Latin characters — text containing Cyrillic, Greek or Chinese characters, or emoji, will stop with an error message.
- The preview is an approximation: the final watermark is placed in PDF points and rotated around a different reference point. With strong rotation or mixed page sizes, the stamp can end up sitting slightly differently.
- For the classic look, set the opacity to 20-40 percent and rotate about -30 degrees — recognizable at a glance without hiding the content underneath.
- A watermark is a visible label, not protection: it sits as a normal text layer on the page and can be removed with PDF editors. For passwords, use the Protect PDF tool.
Frequently asked questions
Can I use an image or logo as a watermark?
No, the browser version stamps text only. You can hint at a brand with your company or product name, but placing a PNG or SVG graphic is not possible here. For that you would need a PDF editor with an image watermark feature.
Does the watermark sit on top of or behind the content?
On top. pdf-lib appends the text after the existing page content, so it is drawn over text and images. That is exactly why the opacity slider matters: at 20 to 40 percent the stamp stays visible without hiding what's underneath. Placing the watermark behind the content is not something this tool can do.
Can the watermark be removed again later?
Not with this tool, and not casually — it becomes part of the page content and shows up in prints too. It is not tamper-proof, though: specialized PDF editors can delete the text object again. Treat it as a clear label, not as copy protection.
Is my PDF uploaded to a server?
No. PDF.js renders the preview and pdf-lib writes the watermark — both run as JavaScript in your browser. The file is read from your device, processed in memory and saved locally. You can verify this in your browser's network panel while using the tool.
Can I watermark only certain pages?
No, the stamp is applied to every page of the document with identical settings. If you only need it on part of the file, split the PDF first, watermark the relevant section and merge the files back together — both tools are available on this site.
Does it work with password-protected PDFs?
Only partially. If the PDF requires a password just to open, the preview already fails and you see an error message. Files that merely carry editing restrictions are processed anyway, but the result can come out unusable. The reliable route is to remove the protection first and add the watermark afterwards.
Is there a file size or page limit?
No fixed limit is built in. The practical ceiling is your device's memory, because the entire PDF is loaded and rewritten in the browser. Documents with hundreds of pages usually work fine; very large scanned files can get slow on phones or older machines.
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