Annotate PDF Online
Highlight, comment, draw and box up a PDF — notes stay in the file, editable in any viewer.
or drop files here
- Highlights, notes, text, boxes and drawing
- Saved as real PDF annotations
- Everything stays on your device
Annotate PDF Online
Annotate a PDF the way reviewers actually work: highlight a line, drop a sticky note, type a comment straight onto the page, draw or box a detail, then save. Highlights, notes, boxes and drawings are written as real PDF annotations, so they stay editable in Acrobat, Preview and Chrome. Text boxes are stamped into the page. Everything runs in your browser — the file is never uploaded, and the free plan covers PDFs up to 100 MB.
How to annotate a PDF
- 1Add the PDF you want to annotate.
- 2Pick Highlight and drag over a line, or choose Note, Text, Draw or Box for the other mark types.
- 3Choose a colour; use Select to click a mark and remove it, and undo or redo any step.
- 4Save the annotated PDF — the file is written on your device.
What you can do in the annotator
- Highlights, sticky notes, boxes and drawings are real PDF annotations, still editable later
- Type a comment straight onto the page with the Text tool
- Six colours, page-by-page marks, undo and redo
- Works on phone, tablet and desktop — nothing to install, nothing uploaded
PDF annotation questions
Do the highlights and notes stay editable?
Yes. Highlights, sticky notes, boxes and drawings are saved as standard PDF annotations, so Acrobat, Preview and Chrome show them in their comment panels and let you edit or delete them later.
Is my PDF uploaded anywhere?
No. The annotator opens and saves the file in your browser, on your own device — there is no upload and no server round-trip.
Can I annotate on a phone?
Yes. Tap a tool and drag with a finger; the page fits the screen and every control meets the 44 px tap-target minimum.
What is the free file size limit?
Free covers PDFs up to 100 MB. Larger files need Pro, which uses the same in-browser tools with higher caps.
Will typed Text stay selectable later?
Text marks are stamped into the page as content, not as a separate annotation layer, so they print and view reliably but are not re-editable like sticky notes.
Can I undo a mistake?
Yes. Undo and redo cover highlight, note, text, draw and box actions in the current session before you save.
Do annotations show in other apps?
Standard annotation types open in Acrobat, Preview, Edge and Chrome. A few niche viewers ignore comments; if someone cannot see marks, open the file in Acrobat or Chrome.
Is this the same as Edit PDF?
No. Annotator adds review marks. Edit PDF changes page content (text, images, pages). Use Annotator for feedback and Edit when the document itself must change.
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