How to Highlight and Draw on a PDF: Free (2026)
How to Highlight and Draw on a PDF: Free (2026)
Marking up a PDF: highlighting key lines, circling a figure, jotting a note, is one of the most common things people need to do with a document, and you don't need expensive software for it. Here's how to highlight, draw, and annotate a PDF for free, right in your browser, without uploading your file.
Highlight and Draw on a PDF (No Upload)
PDF Zone's Edit PDF tool includes highlighting, freehand drawing, shapes, and text, all running locally on your device.
- Open the Edit PDF tool.
- Drag in your PDF.
- Pick a tool from the toolbar:
- Highlighter, drag across text to highlight it in your chosen color.
- Pen / draw: draw freehand to circle, underline, or sketch.
- Shapes: add rectangles, lines, or arrows to point things out.
- Text, type notes directly onto the page.
- Adjust color and thickness as needed.
- Download the annotated PDF.
Because it's browser-based, your markups are saved into a normal PDF that opens anywhere.
Highlighting Text vs. Highlighting an Area
- On PDFs with real text, the highlighter can follow the words for clean, line-by-line highlights.
- On scanned PDFs (which are images), there's no text to grab, so you highlight by drawing a colored box over the area. To highlight the actual words on a scan, run it through the OCR PDF tool first to add a text layer.
Draw and Annotate on Mobile
The tools work in your phone's browser, so you can mark up documents on the go:
- Open the Edit PDF tool in Safari or Chrome.
- Upload the PDF from Files or Drive.
- Use your finger to highlight and draw.
- Download the marked-up file.
Great for signing off on proofs, grading assignments, or reviewing a contract from your phone.
Keep Your Annotations From Being Changed
Annotations can normally be moved or deleted by whoever opens the file. To lock them in place, flatten the PDF after marking it up, your highlights and drawings become part of the page.
Who Uses PDF Markup?
- Students highlight key passages in lecture notes and textbooks and draw diagrams in the margins.
- Teachers circle mistakes, underline strong sentences, and add feedback directly on submitted work.
- Reviewers and editors mark up proofs and drafts without printing a single page.
- Professionals flag clauses in contracts, point out figures in reports, and initial changes.
Because the marked-up file is a standard PDF, you can email it back and the recipient sees your highlights and notes exactly as you left them.
More Ways to Mark Up a Document
- Erase or cover text: see how to erase text and edit a PDF.
- Add a stamp like APPROVED or CONFIDENTIAL: use the Stamp tool.
- Redact sensitive info permanently: see how to redact a PDF.
Frequently Asked Questions
How do I highlight text on a PDF?
Open PDF Zone's Edit PDF tool, choose the highlighter, and drag across the text you want to highlight. Pick your color, then download the highlighted PDF.
How do I draw on a PDF?
In the Edit PDF tool, select the pen or shape tool and draw freehand or add lines, arrows, and boxes directly on the page. Adjust color and thickness as needed.
Can I highlight and draw on a PDF for free?
Yes. The Edit PDF tool is free, has no watermark, and runs entirely in your browser with no upload.
Why can't I highlight the text on my PDF?
It's probably a scanned document, an image with no selectable text. Highlight by drawing a colored box over the area, or run the file through OCR first to add a text layer you can highlight.
Can I annotate a PDF on my phone?
Yes. Open the Edit PDF tool in your mobile browser, upload the PDF, and use your finger to highlight and draw. No app needed.
Is it safe to annotate a PDF online?
With PDF Zone it is, all markup happens locally in your browser and your file is never uploaded, so sensitive documents stay private.
How do I stop people from removing my highlights?
Flatten the PDF after annotating. Flattening merges your highlights and drawings into the page so they can't be moved or deleted.
Do I need Adobe Acrobat to highlight a PDF?
No. The free browser-based Edit PDF tool handles highlighting, drawing, and annotating without a paid Acrobat subscription.
Related: Edit PDF · Stamp PDF · Flatten PDF
Ready to try it yourself?
Highlight text, draw, and annotate a PDF for free in your browser: no uploads, no Acrobat. Mark up documents on desktop and mobile. Step-by-step 2026 guide.
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