Drag and drop PDF files here, or click to upload
Supports batch upload, max 50MB per file
Click the upload area or drag and drop your PDF files directly into the drop zone. This tool supports batch uploading multiple PDF files, with a recommended maximum of 50MB per file. After uploading, a file list will appear below showing each file's name and size.
In the Watermark Settings section, customize the following: Text — enter the text you want to display, such as "Confidential", "Internal Use Only", or your company name; Font Size — adjust the watermark text size from 12px to 72px using the slider; Opacity — control how visible the watermark is, with 20%-40% recommended for a balance of visibility and readability; Text Color — choose from multiple colors, with gray being the most common choice; Rotation — set the tilt angle of the watermark, with 45 degrees being the most popular diagonal style; Position — click the 3x3 grid to select where the watermark appears on each page.
Once configured, the preview area updates in real time to show how the watermark will look. When satisfied, click the "Add Watermark" button. The tool uses pdf-lib.js to process the PDF entirely within your browser, applying the watermark to every page. After processing, you can download the watermarked PDF.
Due to technical limitations, PDFs with special embedded fonts or complex layouts may experience minor changes after watermarking. Always preview before processing. Password-protected PDFs must be decrypted first. Large PDFs (over 100 pages) may take a few seconds to process—please be patient.
Corporate contracts, reports, and proposals often need watermarking before internal distribution or external sharing. Adding a watermark with the company name or a "Confidential" label helps prevent unauthorized copying and distribution. Even if the document is forwarded, the source can be traced through the watermark.
Designers, photographers, and writers sharing preview drafts can protect their work by overlaying semi-transparent watermarks. This allows recipients to view the content while safeguarding the creator's intellectual property rights. It's a simple yet effective way to deter unauthorized use.
Training institutions sending out course materials, exam papers, and lecture notes can add institutional or student-specific watermarks to prevent unauthorized distribution. This is especially useful for online course PDFs, where watermarks serve as a low-cost but effective copyright protection measure.
Government agencies and legal professionals can use watermarks to mark internal notices, meeting minutes, and policy documents with labels like "Internal Use Only" or "Attention: Confidential." This reminds recipients of the document's sensitivity and reduces the risk of information leakage.
PDF watermarks are essentially text or graphic elements overlaid on top of page content. This tool uses the pdf-lib.js library to draw a text object on every page at a specified position, with configurable transparency and rotation. Since the watermark is added as a new content layer, it can be removed using advanced PDF editing software. For stronger protection, consider embedding watermarks at the document level or rasterizing the entire page.
Watermarks and digital signatures serve different purposes. Watermarks are visual indicators meant to deter and inform; they can technically be removed. Digital signatures use encryption to verify document integrity and authenticate the sender. For maximum protection, combine both: use a digital signature to ensure document authenticity, and add a watermark for visual deterrence.
Select parameters based on your use case: Opacity — 20%-40% is ideal; too low makes it invisible, too high obscures content. Color — gray is standard; red conveys urgency; blue fits brand palettes. Position — center is most visible but may cover content; corners are more subtle. Rotation — 45° is the classic diagonal watermark; adjust based on page layout.
PDF/A is an archival standard with three levels (PDF/A-1, PDF/A-2, PDF/A-3). Adding a watermark to a PDF/A file may break PDF/A compliance because the standard restricts modifications. This tool adds standard PDF text objects that are generally well-supported, but if your document requires long-term archival, verify compliance with a PDF/A validation tool after watermarking.
No. This tool processes everything locally in your browser using pdf-lib.js. Your PDF files are never uploaded to any server. All watermarking operations happen entirely on your device, ensuring complete privacy and security.
Currently, the tool supports text watermarks only, with full customization of text content, font size, color, transparency, and position. Image watermark support is planned for a future update.
No. The tool overlays watermark text on top of the existing PDF content using pdf-lib.js without re-encoding or compressing the original pages. The resulting PDF retains all the original content and quality.
Yes. You can select multiple PDF files, and the tool will apply the same watermark settings to each file. After processing, you can download all watermarked files individually. Supports up to 50 PDFs per batch.
Yes. The watermark text supports any Unicode characters including English, Chinese, Japanese, and symbols. Note that some specialized or rare characters may render as squares depending on the PDF reader.
No. The watermark is drawn as a text overlay on top of each page. The page count, page size, and all original content remain unchanged. Only a new text layer is added.
Yes. You can adjust transparency from 0% to 100% via a slider, choose from 9 preset positions, and set a custom rotation angle from -180 to 180 degrees.
Yes. The watermark added by this tool is a standard text overlay. It can be selected and deleted using professional PDF editors like Adobe Acrobat. For stronger protection, consider desktop PDF security software that embeds watermarks at the page content level and rasterizes the page.