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Highlight PDF Online Free — PrivaTools

TL;DR: Upload a PDF, type a search term, and download a copy with every matching occurrence highlighted in yellow.

Highlight every match of a word or phrase in PDF online for free. Auto-find and yellow-highlight all occurrences across the whole document. Free, fast, private.

Using Highlight PDF doesn't require an account, an email address, or a paid plan. Your file is held in temp memory only for the duration of processing, then permanently unlinked. No watermarks, no upsells, no behavioural tracking.

How to Highlight PDF with PrivaTools

  1. Upload the PDF — Select a PDF up to 500 MB containing the text you want to highlight.
  2. Enter your search phrase — Type the word or phrase to highlight. Use the case-sensitive toggle for exact matches.
  3. Pick a highlight color — Choose yellow, green, pink, blue, or orange. Highlights are added as real PDF annotations.
  4. Download the highlighted PDF — Click Highlight. The tool finds every occurrence on every page and writes a new PDF with permanent highlight annotations.

Frequently Asked Questions

Are the highlights real PDF annotations or flattened images?

Real PDF annotations. They render in every PDF viewer and can be removed later if you reopen the file in an editor. Nothing about the underlying text is changed.

Can I highlight multiple phrases at once?

Run the tool once per phrase. Each run preserves previous highlights, so you can layer different colors for different keywords.

Does the highlighter respect case?

Toggle case-sensitive matching for exact-case search; leave it off for case-insensitive flexible matching. Case-insensitive is the default.

Last reviewed 2026-03-20 by the PrivaTools maintainers. Source code on (MIT-licensed, self-hostable).

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