Annotate PDF with highlights

Highlight text passages for emphasis, review, or study — drag over text, pick a colour, save the marked file.

You're studying a textbook PDF and want to highlight key passages. Or you're reviewing a contract and want to mark clauses your team should discuss. Highlights anchor attention.

Flint does highlights properly — they're searchable, they stay with the file, and they don't obscure the text.

Drag over text to highlight

Open annotate PDF, select the highlight tool. Click and drag across text — like selecting in a word processor. Release. The text is now highlighted in your chosen colour. Repeat for additional highlights.

Colours and what they mean

Yellow is default for general emphasis. Red signals concerns. Green signals approvals. Blue is often used for definitions or terms. Develop a convention with collaborators so colours mean something consistent across your reviews.

Adding notes to highlights

Click any highlight to add a comment. The comment attaches to that specific highlight. Reviewer clicks the highlight and sees both the marked text and your note about it. Useful for 'why this matters' explanations.

Highlighting in scanned PDFs

If your PDF is a scanned image without OCR, highlights work on regions, not text — you drag over an area and the area gets coloured. For text-aware highlighting on scans, OCR the document first (convert to Word is one path that OCRs as it converts) and re-import the OCR'd PDF.

FAQ

Can I remove a highlight?

Click to select, delete to remove. Or use the eraser tool in some readers.

Do highlights affect underlying text?

No. They sit on top. Text remains selectable, copyable, searchable.

Will highlights export to Word?

Highlighted text exports as highlighted (in some Word converters). PDF to Word usually preserves highlights.

Can I get a list of all highlighted text?

Some readers export highlights as a summary. Acrobat does; Flint annotations remain in-PDF.

Drag, colour, save. Highlight PDF text.

Try it now

Drop a PDF in and you'll be done in seconds — no install, files private to your account.

More on this

Highlight Text in a PDF | Flint — Flint PDF