FreeAPI

Add Watermark to PDF (Stamp & Sign)

Stamp & Sign

Stamp copyright notices, confidentiality markers (CONFIDENTIAL, DRAFT, PAID) or upload transparent PNG signatures onto PDF pages online in seconds without server uploads.

All Tools

Interactive Tool Console

Client-Side Execution • Runs in browser
Your PDFs never leave your device. Watermarking and removal happen 100% locally in your browser.
Guest Quota: 2/2

Select or Drag & Drop PDF to Watermark

Contracts, invoices, or copyright documents

Live API Integration Public Edge API

Call this tool in your codebase or backend services directly via REST API.

curl -X POST "https://findfreeapi.com/api/v1/tools/pdf-watermark-sign" \
  -H "Content-Type: application/json" \
  -d '{"action":"text","text":"CONFIDENTIAL"}'
POST/api/v1/tools/pdf-watermark-sign
No API Key Required (Public Edge)

Key Standards & Highlights

Stamp diagonal or horizontal text watermarks across all document pages
One-click quick presets: CONFIDENTIAL, DRAFT, PAID, DO NOT COPY
Embed transparent PNG signatures and organizational stamps on final pages
Precise control over opacity, angle, color, and font scale

Frequently Asked Questions

Does stamping a watermark distort the original layout?

No. Watermarks and signature stamps are injected as a non-destructive overlay layer, leaving your original text and page formatting intact.

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