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Annotate PDF Files Online

Highlight, underline, draw and leave notes on a PDF, then save them as real PDF comments.

About Annotate PDF

Annotate PDF files when you review a draft, study a paper or mark up a plan for someone else. Drag across text with Highlight, Underline or Strike out and the mark snaps to the lines of text. Add sticky notes, free text, boxes, circles, arrows and pen drawings, with your choice of color and line width.

Notes, highlights and the other text marks can carry a written comment. Everything is saved as standard PDF annotations, so the recipient sees them in the comments list of Adobe Reader and other PDF apps, and can edit or delete them there. To make the marks permanent, run the result through Flatten PDF.

How to use Annotate PDF

  1. 1
    Open the PDF

    Choose a file to annotate PDF pages right in the browser, or drop it on the page.

  2. 2
    Pick a tool

    Highlight, Underline or Strike out for text, Pen, Box, Circle and Arrow for drawings, Note and Text for comments.

  3. 3
    Mark up and comment

    Drag across text or draw on the page, choose a color and line width, and write a comment in the side panel.

  4. 4
    Save the annotations

    Click Save annotations to download the PDF with your comments.

Why use Cubfile for this

  • Snaps to the text

    Highlights, underlines and strike-throughs follow the lines of text you drag across.

  • Real PDF comments

    Annotations stay editable in Acrobat and other PDF readers, so others can reply to or remove them.

  • Drawing tools

    Pen, boxes, circles and arrows in six colors, with a line width from 0.5 to 12.

  • Notes with text

    Pin a note anywhere, or attach a comment to a highlight.

FAQ

Annotate PDF: questions and answers

How do I annotate PDF files without Adobe Acrobat?
Open the PDF here, pick Highlight, Note or another tool and mark up the pages. Save annotations downloads a copy that shows your comments in any PDF reader.
Can others see and edit my notes?
Yes. Everything is saved as standard PDF annotations, so the recipient can read, reply to or delete them in their own PDF app. When the revised draft comes back, Compare PDF highlights every change against your copy.
Can I annotate PDF scans?
Yes. Pen, shapes, notes and text work on any page. On scans, a highlight covers the area you drag over, because there are no text lines to snap to.
Is it free to annotate a PDF online?
Marking up on screen is free, and saving counts as one task. That's 2 in total as a visitor, 2 a day on a free account, and no limit with VIP.
Who can see my notes while I work?
Only you. The pages are shown in your browser, and the copy saved on our server is deleted automatically an hour later.
Share Annotate PDF with a friendIt runs in any browser, and they can try it without signing up.

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