What are PDF highlights?
When you highlight a passage in a PDF reader, the app usually doesn't paint over the page. It adds aHighlight annotation: a separate object that records which area of the page to shade, in what colour, and often who made it and when. Some readers also let you attach a note to a highlight. Because the highlight is stored apart from the page content, it can be removed again without touching the text.
Does removing a highlight remove the text?
No. This tool removes the highlight annotation, not the underlying PDF page text. The words that were highlighted stay exactly where they were; only the coloured marking on top goes away. After cleaning, the tool compares the page content and page count of the new copy with the original to confirm nothing on the pages changed.
Why do PDF highlights remain after sharing?
Highlights travel with the file. If you mark up a contract, a report or a set of notes and then send the same PDF on, the recipient sees every passage you picked out. That can reveal what you focused on during a negotiation, which figures you questioned, or simply make a final copy look like a working draft. Highlights aren't always obvious when you open the file again on your own device, and some are made by colleagues who reviewed the document before you.
How to remove all highlights from a PDF
- Drop the PDF onto the tool above, or choose it from your device.
- The tool counts the highlights and shows which pages they're on.
- It also lists the other annotations it found, such as comments, underlines, links and form fields. These are kept.
- Select Remove Highlights. A new copy is created, re-opened and checked: highlights must be gone and everything else unchanged.
- Download the cleaned copy. Your original file isn't changed.
One thing to know: some apps store freehand highlighter-pen strokes as drawings rather than Highlight annotations, and highlights that were “flattened” are part of the page itself. This tool doesn't remove either.
How the cleaned copy is checked
“Highlights removed successfully” appears only after the tool re-opens the new file and the numbers agree. It counts the Highlight annotations again, which must be zero. It then compares every other annotation type with the original: comments, underlines, drawings, stamps, links and form fields must all have the same count. The page count and the content of each page must match, and so must the document's metadata and XMP metadata. If any of these differ, or part of the file couldn't be read, you see “Cleaned with limitations” with a list of exactly what didn't match, instead of a success message.
What about notes attached to highlights?
Some readers let you type a note on a highlight. That note belongs to the highlight annotation, so it's removed along with it. Separate sticky-note comments placed next to a highlight are a different annotation and are kept.
Does this remove comments too?
No. Sticky notes, text-box comments and their replies are kept, even when they're on the same page as a highlight. To remove review comments, use Remove Comments From PDF, which shows each comment's author and text first.
What about underlines, drawings and stamps?
They're kept too. This tool deliberately does one thing. If you want to remove underlines, strikeouts, drawings, shapes or stamps as well, use Remove Annotations From PDF. There you choose which types to remove, and links and form fields are still kept.
Does this remove PDF metadata?
No. The author, title, dates, custom properties and XMP metadata are carried over unchanged, and the tool checks that after cleaning. To remove them as well, run the cleaned copy through the PDF Metadata Remover.
Signed and archival PDFs
Removing highlights rebuilds the file, which invalidates any existing digital signature, so the tool asks you to confirm first when it detects a signature structure. For PDF/A files, the PDF/A identification may remain, but the tool doesn't validate PDF/A conformance, so you're asked to confirm that too.
Should I check the PDF before sharing?
It's a good habit. Highlights are only one kind of information a PDF can carry. Run the file through the PDF Privacy Checker to see its metadata, comments and other annotations in one report, then clean what you don't want to send.