How to Draw on a PDF Free: Pen, Shapes, and Highlights

Sometimes a comment box doesn't cut it. You need to circle the paragraph, draw an arrow at the thing that's wrong, sketch where the shelf should go on the floor plan, or just scribble on a document the way you would with a pen and paper. Every device can do this now; the trick is knowing which tool to grab so you're not fighting the software.

In your browser (any computer, nothing to install)

Open our PDF editor and drop your file in.
Pick the draw tool from the toolbar.
Choose a color and stroke width, then draw directly on the page with your mouse, trackpad, or touchscreen.
Made a mess? Undo, or select the stroke and delete it. Drawings stay editable objects until you save.
Download. Your marks are now part of the PDF for anyone who opens it.

The whole thing runs client-side: the file never uploads anywhere, so marking up a lease or a medical form doesn't mean handing it to a server first.

Alongside freehand drawing you get shapes (clean circles and rectangles read better than shaky ovals), arrows, lines, and a highlighter when what you really want is to mark text.

On an iPad or iPhone (the pencil experience)

Apple's built-in Markup is genuinely good, especially with an Apple Pencil:

Open the PDF in the Files app (or tap a PDF attachment in Mail).
Tap the pencil-tip icon, top right.
You get pens, a highlighter, an eraser, and a ruler. Draw away.
Tap Done — the marks save into the file.

Two things people miss: press-and-hold after drawing a rough circle or arrow and Markup snaps it into a perfect shape, and the + button adds text boxes and even your saved signature.

On Android

Open the PDF in Google Drive and tap the pen icon to enter annotation mode: freehand pen, highlighter, eraser. Samsung devices with an S Pen get a richer version of the same idea in their built-in viewer. Or skip apps entirely: our editor works in mobile browsers too, with your finger as the pen.

On Windows and Mac, offline

Windows: Edge (yes, the browser) is quietly one of the best PDF-drawing tools on Windows. Open the PDF in Edge, and the toolbar has a draw pen with color and thickness options. Ctrl+S saves your ink into the file.
Mac: Preview's markup toolbar (the pen icon) has a sketch tool that auto-smooths shapes, plus freehand drawing. Trackpad drawing is awkward; if you have an iPhone nearby, Preview can hand the drawing step to your phone's touchscreen via Continuity.

Drawing tips that make markups clearer

Red for problems, one other color for everything else. A page with five colors of ink reads as noise.
Use shapes for anything rectangular. A drawn box around a paragraph beats a wobbly freehand loop.
Arrow + short note beats a long circle. Point at the thing; explain in five words nearby.
Check whether your marks survived. Some viewers store ink as annotations that other apps can hide or strip. If the markup absolutely must be visible everywhere (a signed-off drawing, for instance), flatten the PDF afterwards to fuse the ink into the pages.

When drawing is the wrong tool

If what you're "drawing" is actually your signature, use a proper signature tool instead — it produces something consistent and reusable rather than a one-off trackpad wobble. And if you're trying to obscure sensitive text, don't draw a black box over it; ink sits on top of text that's still there underneath. Use real redaction, which removes the content itself.