Annotate PDF

Add text notes, highlights, rectangles and review stamps to PDF pages.

Part of the PDF Optimization Suite suite. 100% in-browser private execution with zero cloud storage.

Client-Side Processing
100% In-Browser RAM
No upload
Zero Network Payload
No AI training
Zero Model Scraping
No server queue or size limited
No waiting
Media files stay local; diagnostics are separate. Your media file is processed in your browser and is not uploaded or sent to an AI service. If enabled, anonymous diagnostics may be sent, but they do not contain file contents.

Processing Architecture & Calibration

All media streams are isolated locally inside your device using hardware-accelerated WebAssembly (WASM) and WebCodecs. Zero bytes of audio or video content are ever transmitted to external cloud servers.

How It Works

  1. Drop your audio or video file directly into the browser dropzone.
  2. The client-side engine executes local inference or bit-exact extraction without upload delays.
  3. Audition the 15-second realtime A/B comparison with the Dry/Wet slider.
  4. Export your pristine clean master file with 100% original video track preservation.

常见问题解答

这款工具能做什么？
Add text notes, highlights, rectangles and review stamps to PDF pages.
它基于什么引擎？
它运行在 Drop & Clean 的本地 WebAssembly PDF 引擎上：解析、重写与导出全部在当前标签页的内存中完成，零服务器往返。
这个工具能处理哪些文件？
本页只处理自身的原生格式：文档类工具为 PDF，图片类工具为 JPG／PNG／WebP。引擎会先校验文件再处理，不支持的输入会立即中止，而不是产出损坏的结果。
处理会破坏原始画质或排版吗？
页面级操作重写的是文件结构，不会把内容栅格化；在操作允许的范围内，矢量文字、内嵌字体与图片分辨率都会被保留。
我的文件会被上传吗？
不会。文件只在当前标签页内读取与重写：没有上传、没有服务器排队，任何机器上都不会留下副本。

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