Add professional text watermarks to any PDF document with full control over position, opacity, font size, color, and rotation. Stamp documents with CONFIDENTIAL, DRAFT, your brand name, or any custom text across every page. The watermark is rendered as selectable, high-quality text with Unicode support. Ideal for branding, copyright protection, document status marking, and legal workflows. Upload a PDF and receive a downloadable watermarked file.
{"success":true,"url":"https://pub-6db99bab215e44889f46c4b2a619f8c5.r2.dev/watermarked/20260619/f977168b-1b94-4749-a97a-0e90c2cc6af3.pdf","watermark_type":"text","pages_watermarked":5,"processing_time":"673ms"}
curl --location 'https://zylalabs.com/api/12964/pdf+text+watermark+api/25882/add+text+watermark?text=CONFIDENTIAL BRO&rotation=Optional' \
--header 'Content-Type: application/json' \
--form 'image=@"FILE_PATH"'
注册后,每个开发者都会被分配一个个人 API 访问密钥,这是一个唯一的字母和数字组合,用于访问我们的 API 端点。要使用 PDF Text Watermark API 进行身份验证,只需在 Authorization 标头中包含您的 bearer token。
| 标头 | 描述 |
|---|---|
授权
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必需
应为 Bearer access_key. 订阅后,请查看上方的"您的 API 访问密钥"。
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无长期承诺。随时升级、降级或取消。 免费试用包括最多 50 个请求。
(年度计费可节省 2 个月 🎉)
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The PDF Text Watermark API allows developers to add customizable text watermarks to PDF documents through a simple API request. Upload a PDF file, specify the watermark text, and configure its appearance using options such as position, opacity, font size, color, and rotation. The API processes the document and returns a downloadable version containing the watermark applied across all pages.
Watermarks can be used to identify document status, indicate ownership, display copyright notices, apply company branding, or mark documents for internal and external distribution. Common examples include "CONFIDENTIAL", "DRAFT", "INTERNAL USE ONLY", company names, project identifiers, legal notices, and other custom text labels.
The API supports configurable watermark placement, allowing text to appear in the center of the page or in one of the page corners. Opacity settings can be adjusted to ensure the watermark remains visible while preserving the readability of the original document. Rotation controls make it possible to create diagonal stamps commonly used for confidential and draft documents.
Watermark text is rendered directly into the PDF and supports Unicode characters, making it suitable for multiple languages and international document workflows. Font size and color can be customized to match branding requirements or document policies.
Common use cases include:
Marking confidential documents
Adding draft or review status indicators
Applying company branding to PDFs
Copyright and ownership labeling
Legal and compliance workflows
Contract and agreement management
Internal document distribution
Invoice and report identification
Educational and publishing platforms
Document archiving and record management
Features:
Add text watermarks to PDF documents
Apply watermarks across all pages
Custom watermark text
Adjustable position settings
Configurable opacity levels
Custom font size controls
Custom text color selection
Rotation angle support
Unicode character support
Downloadable PDF output
JSON response format
HTTPS-based API access
The API accepts PDF files as multipart form-data and returns structured JSON containing a download URL for the processed document. It can be integrated into document management systems, workflow automation platforms, web applications, mobile applications, business software, and file processing services that require PDF watermarking functionality.