How to draw on a PDF free — freehand markup in your browser

Some feedback cannot be typed. Circling the wrong dimension on a floor plan, sketching an arrow from a caption to the figure it belongs to, crossing out half a diagram and drawing the corrected version beside it — these are jobs for a pen, not a text box. On paper you would just draw; on a PDF, most tools either cannot do it or make you upload the document to a server first.

The pdfmend editor gives you that pen in the browser. Its Ink tool captures freehand strokes from a mouse, trackpad, or finger and places them on the page as marks you can move and resize. The PDF is opened locally, drawn on locally, and exported locally — there is no upload operation anywhere in the flow.

• The PDF, on your device (up to 100 MiB and 250 pages during the free launch).
• Any modern browser. A touch screen or stylus makes drawing feel natural, but a mouse works fine. No account, and no watermark on the export.

1. Open the editor and choose your PDF. Your browser reads the file directly; nothing is sent to a server.
2. Select the Ink tool in the toolbar.
3. Draw directly on the page — circle, underline, sketch, cross out. Each stroke is captured as you make it, and after every stroke the editor returns to Select automatically. Re-select Ink whenever you want to draw another stroke.
4. Adjust the line width in the Properties panel after drawing, while the stroke is selected. Thin lines suit precise marks on dense drawings; thick lines read clearly on plans viewed at a distance or in small previews.
5. Finished strokes live in an ink box you can drag to reposition or resize from a corner, so a circle drawn slightly off target is fixed by moving it, not redrawing it.
6. Use Undo for a bad stroke and Zoom for detailed areas — drawing zoomed in, then zooming out, is the easiest way to make small marks accurately.
7. Click Export PDF. The marked-up copy is generated in your browser and saved to your device.

The Ink tool takes input from whatever pointer you have, and each behaves a little differently:

• Mouse. Best for deliberate shapes — boxes, arrows, strike-throughs. Long smooth curves take a steady hand; drawing them zoomed in helps.
• Trackpad. Workable for short marks; for anything intricate, zoom in generously so small finger movements translate to fine strokes.
• Touch screen. The most natural option. Drawing with a finger or stylus on a phone or tablet feels closest to pen on paper, which is why the same input method powers the Signature tool.

Whatever the device, line width does a lot of the work: set it in the Properties panel after the stroke, and choose it for how the page will be read, not for how it looks while zoomed in.

Freehand marks rarely land perfectly the first time, and this is where drawing digitally beats a real pen. Every ink stroke sits in its own box after you draw it. Select it and you can drag the whole mark to a new position or pull a corner to scale it — a circle that came out too small grows to fit, an arrow drawn in the margin slides over to its target. Undo and Redo back you up stroke by stroke, and a mark that cannot be saved is deleted and drawn again in seconds. Nothing is permanent until you export.

• Marking up plans and drawings. Circle a problem area on a floor plan, sketch where the outlet should move, and cloud a region for revision — the classic red-pen pass, no paper required.
• Correcting diagrams. Cross out a wrong arrow in a flowchart and draw the right one; annotate a graph with the trend you actually expect.
• Teaching and review. Handwritten-style marks on a student's PDF read as human in a way typed comments do not.
• Quick visual answers. Sometimes "which one?" is answered fastest by circling it and exporting.

Ink combines well with the other markup tools: pair strokes with the Highlight and Sticky tools (see the annotation guide) or add typed labels with the Text tool via the add-text guide. If the freehand mark you need is your signature, the dedicated Signature tool in the signing guide is built for exactly that. And because every stroke happens in your browser, marked-up site plans and confidential drawings stay yours alone — the privacy page has the details.