Highlight PDF Online
Add yellow highlight rectangles to any region of your PDF pages. Customize color and opacity.
Upload PDF
PDF Highlighting
Mark important content visually
Region Selection
Specify rectangular areas on any page to highlight.
Color & Opacity
Choose yellow (default), green, blue, or pink with adjustable opacity.
100% Private
All highlighting runs in your browser via pdf-lib.
FAQ
Highlighting is region-based (rectangles), not text-based. To highlight specific words, place a rectangle over them.
Yellow (default), green, blue, pink, and orange. All with adjustable opacity for subtle or bold highlights.
No — highlights are semi-transparent overlays. Text underneath remains fully readable.
After downloading, no — highlights become part of the page. Re-upload the original PDF to start over.
Watermarks are typically large diagonal text. Highlights are smaller rectangle overlays for specific regions.
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