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Annotate and highlight a PDF

Highlight, underline and strike-through in PDFlick operate on real text selections and snap out to whole words, so a drag that stops halfway through "agreement" still marks the whole word rather than half of it. Pen and marker strokes render under your finger in real time, and sticky notes are visible cards you can drag, resize and recolour — not pins that hide what they say.

Coming Soon iOS 26.2 or later · iPadOS 26.2 or later · macOS 26.2 or later

Also searched as: highlight PDF · PDF markup · draw on PDF · add notes to PDF · comment on PDF

How to annotate and highlight a PDF

On iPhone & iPad

Open the document and tap Annotate.
Pick highlight, underline or strike, then drag across the text — the selection snaps to whole words.
Switch to the pen or marker to draw freehand, or add a sticky note and type into the card.
Drag a note by its body, resize it from the corner, and recolour it from the palette.
Save when finished; annotations are written into the PDF itself.

On Mac

Open the document on the full-size canvas.
Press a bare key to switch tools: H highlight, U underline, S strike, P pen, M marker, E eraser, N note, T text, R rectangle, O circle, A arrow.
Right-click any annotation to delete it; the cursor changes to a crosshair to draw and an I-beam over text.
⌘Z undoes, ⌘D duplicates, esc deselects, ⌘S saves.

What makes it different

Text markup works on genuine text selections rather than drawn rectangles, so highlights track the glyphs even on justified or multi-column layouts.
Selections snap out to whole words, so a clipped drag never marks up a partial word.
Underlines are drawn through Core Text so they reach the page correctly, not just in the editor preview.
Sticky notes stay visible as cards with their contents showing, and can be resized by the corner.
Eleven tools are on bare-key shortcuts on the Mac, so you can switch without going back to the toolbar.

Annotate PDF — questions

Do the highlights work on scanned pages?

Text markup needs a text layer. Run OCR / Searchable on the scan first and the recognized text becomes selectable, after which highlight, underline and strike all work normally. The pen and marker work on any page regardless.

Will my annotations show up in other PDF readers?

Yes. Markup is written as standard PDF annotations into the file, so Preview, Acrobat and other readers display it.

Can I remove an annotation after saving?

Yes — select it and delete, or right-click it on the Mac. Annotations remain individually editable objects rather than being burned into the page.

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