Add custom text watermarks to every page of your PDF. Choose position, opacity, rotation, font size, and color. All processing happens in your browser.
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Applying watermark...
Stamp any text watermark onto every page of your PDF in three simple steps — no software installation required.
Drag and drop your PDF file into the upload area, or click "Choose PDF File" to browse your device. The tool accepts any standard PDF document regardless of page count, file size, or complexity. Once uploaded, the first page renders instantly as a preview so you can see how the watermark will look before committing to the final output.
Type your watermark text — anything from "CONFIDENTIAL" to your company name or "DRAFT". Choose a position: Center places it in the middle, Diagonal stamps it at a 45-degree angle across the page, Top or Bottom anchors it to the respective edge. Adjust the font size, set the opacity to control transparency, and pick any color using the color picker. The live preview updates in real time so you can fine-tune every detail.
Click the Download button and your watermarked PDF is saved to your device in seconds. The watermark text is embedded on every page of the document using the Helvetica font. Your original PDF is never modified — the tool creates a brand-new file with the watermark applied, so your source document remains untouched and safe.
A faster, safer, and more flexible way to watermark PDF documents — built for everyone.
There is no premium tier, no usage cap, and no hidden paywall. ConvertKr's PDF watermark tool is free for everyone, whether you need to watermark a single document or process dozens of files in a row. Essential file tools should be accessible without a subscription or per-file charge.
Unlike most online PDF tools, your files never leave your device. All watermarking happens locally in your browser using JavaScript and the pdf-lib library. There is no server upload, no temporary cloud storage, and no risk of your confidential documents being accessed by anyone else.
Control every aspect of your watermark: text content, position, font size, opacity, and color. Whether you need a subtle draft indicator or a bold confidentiality stamp, the tool adapts to your exact requirements with real-time preview feedback.
The watermark is automatically applied to every page of your PDF document, ensuring consistent protection throughout the entire file. Whether your document has two pages or two hundred, every page receives the same watermark in the same position with the same formatting.
See exactly how your watermark will appear before downloading. Every change to the text, position, font size, opacity, or color updates the preview canvas instantly. No guesswork, no surprises — what you see is what you get in the final PDF.
ConvertKr never adds its own watermarks, logos, or branding to your output files. The only watermark on your PDF is the one you create. Your downloaded file is clean, professional, and ready to share with clients, colleagues, or stakeholders.
Everything you need to know about adding text watermarks to PDF documents.
Why Watermark a PDF? Watermarking PDF documents serves multiple important purposes in professional and personal workflows. The most common reason is to mark documents as confidential, draft, or for internal use only. When you share a document that is still under review, stamping "DRAFT" across every page ensures that recipients understand the content is not finalized and should not be distributed or cited as authoritative. Similarly, marking files as "CONFIDENTIAL" or "DO NOT DISTRIBUTE" provides a clear visual indicator of the document's sensitivity level, helping to prevent accidental sharing with unauthorized parties. Businesses also use watermarks for branding purposes, placing their company name or logo text on reports, proposals, and presentations to reinforce brand identity even when documents are printed or forwarded.
Choosing the Right Watermark Settings The effectiveness of a watermark depends on finding the right balance between visibility and readability. A watermark that is too opaque will obscure the underlying content and make the document difficult to read. A watermark that is too transparent may go unnoticed entirely. For most use cases, an opacity between 20% and 40% works well — the watermark is clearly visible but does not interfere with the document content. The diagonal position is the most popular choice because it covers a large area of the page and is difficult to crop out or cover up. Center placement works well for single-word stamps on documents with wide margins. Font size should be proportional to the page size; 48 to 72 points typically provides good coverage on standard letter or A4 pages without overwhelming the content.
Common Watermark Use Cases Legal professionals frequently watermark contracts, agreements, and court filings to indicate draft status during the review process. Real estate agents watermark property listings and appraisal documents shared with prospective buyers. Academic institutions watermark exam papers and grading rubrics to prevent unauthorized redistribution. Publishers watermark advance review copies of manuscripts sent to reviewers and media contacts. Financial institutions watermark internal reports, audit findings, and compliance documents. Government agencies watermark classified or restricted documents with appropriate handling instructions. In each case, the watermark serves as a persistent visual reminder of the document's status, sensitivity, or ownership that remains visible whether the file is viewed on screen, printed on paper, or shared electronically.
Technical Details and Quality ConvertKr's PDF watermark tool uses the pdf-lib JavaScript library to embed text directly into the PDF page content stream. This means the watermark becomes part of the PDF itself, not a separate overlay or annotation that can be easily removed. The Helvetica font is used for maximum compatibility across all PDF viewers and operating systems. The watermark text is rendered at the exact position, size, opacity, and color you specify, and because the operation modifies the PDF at the content level, the output file is a fully valid PDF that works in every reader, printer, and archival system. All processing runs entirely in your browser — your PDF file is never uploaded to any server, ensuring complete privacy and security for sensitive documents.
Everything you need to know about watermarking PDFs with ConvertKr.
ConvertKr offers four position options. Center places the watermark in the middle of each page, ideal for single-word stamps. Diagonal rotates the text at a 45-degree angle across the page, providing maximum coverage and making it difficult to crop out. Top anchors the watermark near the top center of the page, and Bottom places it near the bottom center.
Yes. You can type any text you want in the watermark text field. Common examples include "CONFIDENTIAL", "DRAFT", "DO NOT DISTRIBUTE", "SAMPLE", "COPY", or your company name. The text can be as short or as long as you like, though shorter text generally produces cleaner results at larger font sizes.
For most use cases, an opacity between 20% and 40% works best. This makes the watermark clearly visible without significantly obscuring the underlying document content. Use higher opacity (50-70%) when you want the watermark to be very prominent, such as on sample documents. Use lower opacity (10-20%) for a subtle background effect.
Absolutely. All PDF watermarking happens entirely in your browser using JavaScript and the pdf-lib library. Your files are never uploaded to any server, and we cannot see, access, or store your documents. Once you close the browser tab, all data is gone. This makes ConvertKr safe for confidential documents, legal files, financial records, and personal information.
Yes. The watermark is applied uniformly to every page of the PDF document. You do not need to configure anything extra — the tool automatically iterates through all pages and stamps the watermark with the same text, position, size, opacity, and color on each one.
The watermark is permanently embedded into the PDF content. Once you download the watermarked file, the text cannot be easily removed. This is by design — watermarks are meant to be persistent. Always keep a copy of your original unwatermarked PDF so you can re-watermark with different settings or share the clean version when appropriate.
The tool uses Helvetica, one of the standard PDF base fonts. This ensures maximum compatibility across all PDF viewers, operating systems, and devices without requiring any font embedding. Helvetica is a clean, professional sans-serif typeface that reads well at all sizes and opacity levels.
Yes. ConvertKr runs entirely in your web browser, so it works on smartphones and tablets just as well as on desktop computers. There is nothing to install — if your device has a modern browser with JavaScript enabled, you can watermark PDFs on the go. The interface is fully responsive and optimized for touch screens on iOS and Android.
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