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How to Highlight Text in a PDF — Free Highlighter Tool | PDF AI Work Blog

PDF AI Work Team·July 28, 2026

Mark up important passages in any PDF with the Highlight PDF tool. Choose from multiple colors, adjust opacity, and highlight text like you would on paper — without printing.

When Highlighting Helps

  • Studying: Mark key concepts in textbooks and papers
  • Reviewing: Call attention to specific clauses in contracts
  • Collaborating: Show teammates which sections need changes
  • Research: Color-code different themes or findings
  1. Open Edit PDF
  2. Upload your PDF
  3. Select the Highlight tool
  4. Drag over text to highlight
  5. Choose color and opacity
  6. Download the highlighted PDF

Also in the editor: Annotate PDF for comments, Draw on PDF for freehand markup.

Free, no signup. Highlight your PDF now.

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