How To Annotate a PDF on Windows (3 Easy Ways)

When you work with PDFs on Windows, sometimes you want to highlight key points, add comments, draw on diagrams, or sign off changes without printing anything.

On Windows, you’ve got three main options to annotate PDFs:

• Microsoft Edge, built into Windows

• Smallpdf PDF Annotator, in your browser

• Free desktop PDF readers with markup tools

Below, we’ll walk through each method, show you when to use which, and explain why starting with Smallpdf often gives you the smoothest experience.

→ If you’re a Mac user and you’ve landed here for some reason, we suggest you jump over to this article for how to annotate a PDF on Mac.

If you just need a fast answer, here’s the short version:

1. Smallpdf (online, best all-rounder)

• Go to Smallpdf PDF Annotator.

• Upload your PDF.

• Highlight, draw, add text, or images.

• Download your annotated PDF.

Quick start: Use the annotator below to upload or drag-and-drop your PDF and start adding highlights, text, or drawings.

2. Microsoft Edge (built-in, simple markup)

• Right-click your PDF > “Open with” > “Microsoft Edge.”

• Use the toolbar to highlight, draw, or add notes.

• Press Ctrl+S to save.

3. Desktop PDF apps (installed, offline)

• Open your PDF in a desktop PDF reader.

• Use its comment / annotate tools.

• Save a new copy with your changes.

If you’re unsure where to start, try Smallpdf first for the broadest set of free annotation tools.

Smallpdf’s PDF Annotator gives you a full set of markup tools in your browser. You don’t need to install anything, and you can work from any Windows device with internet access.

Step-By-Step: Annotate a PDF With Smallpdf

Step 1: Open Smallpdf PDF Annotator

Go to the Smallpdf website and open the PDF Annotator feature.

Step 2: Upload your PDF

Drag and drop your file into the upload area, or click “Choose Files” to pick it from your device, Google Drive, Dropbox, or OneDrive.

Step 3: Pick your annotation tools

Use the top toolbar to choose:

• Highlight

• Pen / freehand drawing

• Text boxes

• Shapes (arrows, rectangles, etc.)

• Image insertion

Step 4: Customize your markup

Adjust:

• Color

• Line thickness

• Font size

• Position and rotation for shapes and images

Step 5: Add advanced edits if needed

You can also:

• Insert eSignatures

• Add or delete pages

• Rearrange page order

• Merge in other PDFs before or after annotating

Step 6: Download or share your file

When you’re done, click “Download” to save the annotated PDF, or export it back to cloud storage.

Why Smallpdf Is Often the Best Choice

• It works in any browser on Windows 10 or 11.

• No installation or registration is needed for basic use.

• Add comments, highlights, shapes, images, and signatures.

• Pro users can use OCR to make scanned PDFs searchable and easier to annotate.

• Files are protected with TLS encryption and auto-deleted after a short period.

If you work with PDFs regularly on Windows and need more than a quick highlight, this is usually the best place to start.

Microsoft Edge comes pre-installed on Windows and includes a basic PDF viewer with annotation tools. It’s great for quick one-off markups when you don’t want to open anything else.

Step-By-Step: Use Edge To Annotate PDFs

1. Open your PDF in Edge:

   • Right-click the PDF on your computer.

   • Select “Open with” > “Microsoft Edge.”

2. Show the annotation toolbar: When the PDF opens, you’ll see a toolbar at the top with markup options.

3. Choose a markup tool: Common tools include:

   • Draw: Freehand pen with color and thickness options

   • Highlight: Select text and apply color

   • Add note: Small comment icon with text

   • Erase/undo: Remove mistakes quickly

4. Add your annotations: Click and drag to highlight text, draw shapes, or click to place notes.

5. Save your changes:

   • Click the “save” icon.

   • Press Ctrl+S and choose where to save the updated PDF.

When Edge Is Enough (and When It Isn’t)

Edge works well for:

• Quick highlights or simple notes

• Reviewing a short contract or report

• Marking up a single file offline

It’s less ideal if you:

• Need to insert images or stamps

• Want to reorder or merge pages

• Need OCR for scanned PDFs

• Want a more polished, professional layout

In those cases, it’s better to switch to Smallpdf.

If you often work offline, a desktop PDF app on Windows can be useful. Many free PDF readers include basic annotation features like comments, shapes, and highlights.

Typical Steps in Desktop PDF Apps

While each app looks a bit different, the process is usually similar:

1. Open your PDF: Launch your PDF reader and open the file you want to annotate.

2. Find the comment / annotate tools: Look for a “Comment,” “Annotate,” or “Markup” section in the toolbar.

3. Choose annotation types: Most apps offer:

   • Highlights, underlines, strikethrough

   • Sticky notes or comment bubbles

   • Drawing tools and shapes

   • Text boxes

4. Save an annotated copy: Use “Save As” to keep your original PDF unchanged and create a new annotated version.

When a desktop app makes sense

Desktop PDF apps are useful when you:

• Need an offline option

• Work with large PDFs and don’t want to upload them

• Prefer a traditional installed program

They’re usually less flexible than Smallpdf for things like cloud storage, quick sharing, or combining annotation with other actions like compressing or converting.

Here’s a quick comparison to help you choose.

If you’re not sure, start with Smallpdf. You’ll get the most complete annotation experience with the least setup.

Annotating PDFs on Windows helps you:

• Review faster - Highlight changes, circle errors, and add comments right where they matter.

• Communicate clearly - Visual markup avoids confusion and cuts back on long email threads.

• Collaborate better - Share one annotated file instead of tracking multiple versions.

• Stay paper-free - Sign, mark up, and approve documents without printing anything.

With the right tool, you can move from reading to reviewing in seconds.

We’ve built our online PDF Annotator to slot neatly into your Windows workflow:

• Full markup toolkit - Highlights, pen, text, shapes, images, and signatures in one place.

• Smart extras - Reorder pages, merge other PDFs, compress large files, or convert formats without leaving the browser.

• Works with scanned PDFs - Use OCR to turn scans into searchable, editable text, then annotate as needed.

• Secure by design - TLS encryption, ISO-certified security standards, and automatic file deletion after a short time.

If you often annotate PDFs on Windows, keeping Smallpdf open in a browser tab can save a lot of time across your week.

If you’re ready to try it yourself, open Smallpdf’s PDF Annotator in your Windows browser, upload a file, and start highlighting. You’ll see how fast annotating a PDF on Windows can feel when everything just works.