Are documents uploaded while they are processed?
No. Files are read into browser memory, processed with Canvas and a local pdf.js worker, then downloaded through a temporary object URL.
Private document protection in your browser
Document watermarker
Use an automatic date-and-code watermark or write your own for images or PDFs, flatten the result, and place multiple image sides on one A4 page. Files never leave your browser.
Images and PDFsWavy anti-removal patternNo uploads or document telemetry
1. Choose document
One PDF, or up to four JPG, PNG, or WebP images.
2. Define permitted use
Optional: use these fields to build the watermark text for you.
0 words
Edit this directly. The last text you use stays on this device.
3. Choose protection
Ready to process locally
Protected output
Generated locally in this browser
Preview appears here
Choose a document and define its permitted use. The finished copy will be flattened so the watermark is not a removable PDF text layer.
Local pipeline
From private source to restricted copy
- 01
Open locally
The File API reads bytes directly from your device. No upload endpoint exists in this workflow.
- 02
Render and protect
Canvas draws a unique, irregular wave pattern using browser cryptographic randomness.
- 03
Flatten and download
The protected pixels are exported as PNG or rebuilt into a PDF with no removable watermark text layer.
Privacy boundary
The tool is designed for identity documents and other sensitive copies. Its processing path stays inside browser memory.
- No API route receives source files or generated output.
- The bundled pdf.js worker runs from this site, not a third-party CDN.
- Watermark text, recipient, purpose, filenames, and document pixels are not sent to analytics.
- Temporary result URLs are revoked when you reset or leave the page.
Practical limits
- One PDF or up to four JPG, PNG, or WebP images per run.
- Selected files may total up to 50 MB. Image pixel dimensions are preserved; very large images may fail if the browser cannot allocate enough memory.
- Encrypted PDFs and image formats without native browser decoding are not supported.
- Watermarking discourages reuse but cannot guarantee prevention of every sophisticated manipulation.
Frequently asked questions
Can I put the front and back of an ID on one page?
Yes. Select both images and choose ‘Stack on one A4 page’. Each side is watermarked before the A4 sheet is assembled.
Do I have to add a recipient and purpose?
No. They are optional helpers for building the watermark text. You can edit that text directly or use an automatic date and unique code.
Can the watermark be selected or removed as PDF text?
No. Pages are flattened into protected pixels before PDF export. The watermark is not stored as a separate editable text layer.