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添加水印

为PDF文件添加文本或图像水印。保护和品牌化您的文档。

上传PDF文件

拖放PDF文件到此处。

开发者 API

可通过 API 调用

使用 PDF Tools API 自动化此 PDF 工作流。每次成功请求消耗 1 Credit，处理失败会自动退还。

/api/external/pdf-tools/add-watermark每次成功请求 1 Credit输出：result.pdf
API 文档获取 API Key
curl -X POST https://itextmaster.com/api/external/pdf-tools/add-watermark \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'file=@input.pdf;type=application/pdf' \
  -F 'options={"text":"Confidential","opacity":0.3}' \
  --output result.pdf

关于此工具

添加水印允许您在PDF文档上放置文本或图像水印。水印可以指示文档状态（草稿、机密）、添加品牌或阻止未经授权的复制。

自定义水印的位置、大小、不透明度、旋转和颜色。应用到所有页面或选择特定页面。该工具支持文本水印和图像水印。

所有处理都在您的浏览器本地进行，确保您的文档保持私密。

如何使用

  1. 上传PDF文件

    拖放您的PDF文件或点击选择文档。

  2. 创建水印

    输入文本或上传图像作为水印。调整位置、大小、不透明度和旋转。

  3. 应用并下载

    点击应用添加水印并下载更新后的PDF。

使用场景

文档保护

添加"机密"或"草稿"水印以指示文档状态。

品牌文档

为官方文档添加公司标志或名称。

版权声明

添加版权信息以保护知识产权。

Practical guide

Why choose local processing?

  • Business PDFs can contain contracts, invoices, identity details, or internal business information, so keeping processing in the browser reduces exposure.
  • The website tool is free to use with no usage limits and does not require sign-in.
  • Local processing also keeps iteration fast: adjust options, preview the result, and export a branded PDF without waiting for an upload queue.

Best files for this tool

  • Best for PDF files that open correctly in a modern browser and are not intentionally damaged or restricted.
  • Works well for everyday business, school, legal, finance, and personal documents where you need a branded PDF.
  • For very large files, close unused tabs and process one batch at a time so the browser has enough memory.

Common limitations

  • Encrypted or permission-restricted PDFs may need to be unlocked before processing.
  • Scanned pages, unusual fonts, complex layers, and damaged files can reduce accuracy or processing speed.
  • Browser memory and device performance matter more for local tools than for upload-based services.

Local processing vs upload-based tools

  • Local tools keep routine website processing on your device, while upload-based tools send files to a remote server.
  • Upload-based services can move heavy work off your computer, but they add transfer time and require trusting a server with your files.
  • Use the API when you intentionally need server-side automation; use the website when you want private manual processing.

What to do if processing fails

  • Try a smaller file, a shorter page range, or one file at a time if the browser runs out of memory.
  • If a PDF is encrypted, damaged, or restricted, unlock or repair it first and then retry the workflow.
  • If the output looks wrong, check whether the source file uses scans, complex transparency, form fields, or unsupported embedded objects.

API automation

Automate apply text or image marks with the PDF Tools API. Each successful request uses 1 Credit, and every signed-in user receives 100 free API Credits each month.

View API automation docsCreate API Key

常见问题

可以使用图像作为水印吗？

是的，您可以上传PNG、JPG或SVG图像作为水印。

可以使水印半透明吗？

是的，您可以调整不透明度，从完全透明到完全不透明。

可以对不同页面应用不同的水印吗？

该工具对选定的页面应用相同的水印。对于不同的水印，需要多次处理文档。

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