100% Free  ·  No Signup  ·  No Upload

PDF Annotator Free

Add comments, highlights and notes to PDF. Works entirely in your browser. Your files never leave your device.

Open PDF Annotator Free
No file uploadNo account needed100% privateWorks offlineAlways free

✏️ Add sticky notes, text highlights, and comments to any PDF. Everything runs in your browser.

📄

Drop PDF here or click to upload

What is PDF Annotator?

PDF Annotator is a free browser-based PDF tool powered by PDF-lib. Your documents are processed entirely in your browser and never sent to any server. Works with any standard PDF file. No Adobe Acrobat or software installation needed.

This tool lets you add comments, highlights and notes to pdf without installing any software or creating an account. Everything runs directly in your browser for maximum privacy. Your files and data never leave your device.

Use it for quick tasks at any time from any device — desktop, tablet or mobile. No subscription, no ads, no limits.

⚡
Instant results
No server processing or wait
🔒
100% private
Files stay on your device
💰
Always free
No subscription or fees
📱
Mobile ready
Works on any device

How to use PDF Annotator

  1. Upload your PDF file by clicking or dragging it into the upload area
  2. Set the options specific to this PDF operation
  3. Click the action button — all processing runs locally in your browser
  4. Download the output PDF file to your device

Why use OnlineToolsPlus?

PDF tools on OnlineToolsPlus use PDF-lib — a JavaScript PDF engine that runs locally in your browser. Your documents are never uploaded to a server, which means no privacy risk for sensitive contracts, financial documents or personal files. With 25+ free PDF tools covering merging, splitting, compressing, editing and converting, you have a complete PDF toolkit at no cost.

Frequently asked questions

Is this tool free to use?
Yes, completely free. No subscription, no account, no payment required. All tools on OnlineToolsPlus are free with no hidden costs.
Is my data uploaded to a server?
No. All processing runs locally in your browser. Your files, text and data never leave your device.
Does it work on mobile and tablet?
Yes. All tools are fully responsive and work on any device — desktop, smartphone or tablet. Touch input is fully supported.
Is there a usage limit?
No. Use the tool as many times as you need. There are no daily limits, rate limits or quotas.
Does it work offline?
Yes. Once the page has loaded, most tools work without an active internet connection. Tools that fetch live data (like currency rates) require a connection.
What browsers are supported?
Chrome, Firefox, Safari, Edge and any modern browser are all fully supported. For best performance, use the latest version of Chrome or Firefox.

More PDF Tools

Image to PDFConvert JPG/PNG/WebP images to a PDFPDF MergerCombine multiple PDF files into onePDF CompressorReduce PDF file size in your browserPDF Page CounterCount the number of pages in any PDFPDF to TextExtract all text content from a PDF

Last updated: April 11, 2026

View all 200+ free tools →