Guides · Practical guide · Updated 23 October 2026

How to highlight text in a PDF

Color highlighting helps when reviewing a contract, studying or providing comments. In Indy PDF Studio, you can use the highlighter and other drawing tools. First, test the color and thickness on one page to ensure the original content remains readable.

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Step by step

Open the PDF and go to the page with the important passage.
Select the highlight tool and set the appropriate color and thickness.
Highlight a short section and check that the highlight covers the correct place.
Add a text note, arrow or other available shape as needed.
Export the PDF and open it again to verify the visibility and placement of the notes.

Highlighting a Scan

In a scan, the text is part of the image. Use OCR for recognition and further text editing. Drawn markings can indicate a place in the image, but they do not create text from the image itself.

Use Understandable Meaning of Colors

For example, yellow can indicate important information and another color can indicate questions to be completed. Describe the meaning to the recipient verbally. Do not rely only on color, as the document may be read in black and white or with poor color resolution.

Highlighting Does Not Hide Anything

A colored line or drawn rectangle does not securely remove the original content. Do not assess the security of a sensitive document only based on what is visible on the screen.

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