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Highlight PDF

Mark up important passages, key findings, and critical sections with customizable highlights. Choose from multiple colors and adjust opacity so the underlying text stays readable. All processing happens in your browser — your documents remain private.

Upload your PDF

Drag and drop, or click to browse

100% private — processed locally

Multiple Colors

Choose yellow, green, blue, pink, or any custom color from the full color picker. Use different colors to categorize content.

Adjustable Opacity

Control highlight transparency with a simple slider. Keep text readable while making highlights clearly visible.

Non-Destructive

Highlights are overlaid on the PDF without altering the original content. The underlying text and images remain untouched.

How to Highlight a PDF

  1. 1

    Open PDFlys and upload your PDF document.

  2. 2

    Select the Highlight tool from the toolbar.

  3. 3

    Choose your preferred highlight color and opacity level.

  4. 4

    Click and drag over the areas or text you want to highlight.

  5. 5

    Download the highlighted PDF with all markups permanently embedded.

FAQ

Can I highlight text on a scanned PDF?▾
Yes — the highlight tool draws colored overlays on any PDF, regardless of whether it contains selectable text. It works on scanned documents, image-based PDFs, and regular text PDFs.
Can I remove a highlight after adding it?▾
Yes. Click to select any highlight rectangle and press Delete to remove it. You can also use Ctrl+Z (Cmd+Z on Mac) to undo recent actions.
Will highlights appear when I print the PDF?▾
Yes — highlights are permanently embedded in the PDF file and will be visible when printed, just like they appear on screen.
Can I use different colors for different topics?▾
Absolutely. Switch highlight colors at any time using the color picker. Many users use yellow for key points, green for definitions, and pink for action items.
Does highlighting change the original PDF text?▾
No. Highlighting is a non-destructive overlay. The original text, fonts, and formatting underneath remain completely unchanged.

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