Watermark PDF API for Developers
Feature
Add DRAFT / CONFIDENTIAL / branded watermarks to protect and identify documents.
Use cases
Where watermark helps
- Mark drafts during review
- Stamp CONFIDENTIAL for sharing
- Overlay company logo on every page
- Tiled watermarks across entire pages
- Apply cohort / term branding
- Watermark images (photos, screenshots)
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Add watermark to PDF — copy-paste into your stack
curl -X POST https://pdfapihub.com/api/v1/watermark \
-H "CLIENT-API-KEY: your_api_key_here" \
-H "Content-Type: application/json" \
-d '{
"file_url": "https://example.com/document.pdf",
"text": "CONFIDENTIAL",
"opacity": 0.15,
"angle": 30,
"position": "center",
"output_format": "url"
}'Parameters
What you control
file_url / file
required
Watermark by URL or upload a file.
text
optional
Watermark text. Defaults to CONFIDENTIAL if no image provided.
watermark_image_url
optional
URL to a logo/image to overlay instead of text (PNG/JPG).
color
optional
Hex color for text watermark. Default #000000.
opacity
optional
0.0–1.0 (default 0.15).
angle
optional
Rotation in degrees (default 30).
position
optional
center, top-left, top-right, bottom-left, bottom-right, top-center, bottom-center.
mode
optional
single (default) or tiled (repeats across page).
output_format
optional
file / url / base64 / both