PDF watermark guide
How to add a watermark to a PDF without uploading it
A watermark can mark a document as DRAFT, CONFIDENTIAL, a sample, or your own work. For supported PDFs, the watermark can be added inside the browser without sending the file to a remote processor.
Text watermark or image watermark?
Text watermark
Best for labels such as DRAFT, CONFIDENTIAL, SAMPLE, a project name, or a short ownership notice.
Image watermark
Useful for a logo or mark. Kukureku currently supports PNG, JPG, and JPEG watermark images.
How to watermark a PDF with Kukureku
1. Choose the PDF
Add one PDF up to 25 MB. The current watermark workflow processes the selected document locally in your browser.
2. Choose text or an image
Enter watermark text or choose a supported image, then adjust position, size, opacity, and rotation.
3. Apply and review
Kukureku applies the selected watermark to every page. Open the downloaded result and check that important text, signatures, and diagrams remain readable.
Make the watermark visible without ruining the document
A watermark should communicate status or ownership without making the document hard to read. Large diagonal text with moderate transparency works well for labels such as DRAFT or CONFIDENTIAL because it is difficult to miss but can still leave the page content visible.
A logo usually works better at a lower opacity and a quieter position. Always inspect several pages because a watermark that looks fine over empty space may cover important content on a denser page.
A watermark is a label, not access control
Watermarking can discourage casual reuse and make document status clearer, but it does not encrypt a PDF or prevent someone with the file from viewing it. Use appropriate access controls, encryption, and sharing policies when confidentiality requires stronger protection.
Why local watermarking can matter
Draft agreements, internal reports, and private proofs are often exactly the documents users prefer not to upload unnecessarily. Local browser processing keeps the supported watermark operation on the device while ordinary website requests remain separate.
Learn how no-upload PDF processing works