Skip to content

How to highlight and annotate a PDF

Marking up a PDF is how most documents get reviewed: highlight what matters, comment on what needs changing, circle the thing everyone keeps missing, and send back one file the other person can open without installing anything.

This guide covers the annotation tools available, and how to mark up a document so the feedback is actually usable at the other end.

Open the Edit PDF tool

The annotation tools

All of these live under Annotate in the mode bar, and everything you place can be moved, resized or deleted before you export.

  1. 1Highlight — drag a translucent colour across a passage, exactly as you would on paper.
  2. 2Comment and sticky note — attach a note to a specific spot on the page for a reviewer.
  3. 3Free draw — sketch with the pen to circle, tick, cross out or scribble a correction.
  4. 4Shapes — rectangles and circles to frame a region, lines and arrows to point at it.
  5. 5Stamp — mark a document approved, draft or confidential in one action.

Annotating for someone else to act on

A page covered in yellow tells the recipient nothing. Highlight the specific clause or figure at issue, not the whole paragraph around it.

Pair a highlight with a comment saying what you want done. "Highlighted" is ambiguous; "this date contradicts clause 4" is a task someone can complete.

Use colour consistently and say what the colours mean if it is not obvious — for example yellow for questions, red for errors, green for approved.

An arrow beats a description. Pointing at the cell in the table is faster to write and impossible to misread.

Annotations vs. editing the document

Annotating leaves the document intact and adds a layer of commentary on top. That is what you want when reviewing someone else's work — the original wording stays visible alongside your remarks, so they can see exactly what you were reacting to.

Editing changes the document itself. Use that when you are the author and you want the correction made rather than requested. Both modes work on the same file in the same session, so you can annotate a draft, then make the agreed changes directly once feedback is settled.

Sending the marked-up file

When you download, the annotations are written into the pages, so they appear for anyone who opens the file in any viewer — no special software and no risk of comments being invisible at the other end.

The trade-off is that flattened annotations are part of the page rather than removable objects. If the recipient will need a clean copy too, send the original alongside the marked-up version.

Frequently asked questions

Can I highlight text in a scanned PDF?

You can drag a highlight over any area of any page, including a scan. On a scan you are highlighting a region of the image rather than selecting words, so drag over the area you mean.

Will my annotations show up for other people?

Yes. They are written into the pages when you download, so they appear in every PDF viewer without any special software.

Can I remove an annotation after adding it?

Yes, at any point before you download — select it and delete, or use undo. Once exported, annotations are part of the page.

Can I use different highlight colours?

Yes. Choose a colour before you drag, which makes it easy to separate questions from errors from approvals.

Is there a limit on how many annotations I can add?

No. There is no cap on annotations, pages or documents, and no account is required.

Ready to try it?

Edit text, highlight, draw, sign and annotate a PDF, then download it.

Use Edit PDF