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PDF Guide

How to Highlight Text in a PDF

By Ayaz · Updated July 2026 · 5 min read

You're reading a PDF and you need to mark important text. You could print it and use a real highlighter, but that's wasteful. You could copy the text into a document, but that's slow. Or you could just highlight it right in the PDF.

Why highlight PDFs?

  • Study: Mark key concepts in textbooks and articles.
  • Review: Highlight important sections for later reference.
  • Collaboration: Share highlighted documents with colleagues.
  • Research: Mark quotes and references for papers.

How to highlight text in a PDF

  1. Open PDFly's Highlight PDF tool.
  2. Upload your PDF.
  3. Click and drag over the text you want to highlight.
  4. Choose your highlight color — yellow, pink, green, blue, or purple.
  5. Download your highlighted PDF.

Tips for effective highlighting

  • Use color coding: Use different colors for different types of information.
  • Highlight sparingly: Too much highlighting defeats the purpose.
  • Review your highlights: Go back to your highlighted sections for quick review.
  • Combine with notes: Add notes alongside highlights for context.

Need to highlight a PDF?

Highlight text in seconds — no uploads, no signup.

Open Highlight PDF Tool

Frequently Asked Questions

Can I remove highlights later?

Yes — most tools let you undo or clear highlights before saving.

Can I highlight scanned PDFs?

Yes — highlights work on any PDF, including scanned documents.

Do highlights affect PDF quality?

No — highlights are added without changing the original content.