# How to annotate a PDF on a Mac > On a Mac, open the PDF in Preview, click the Show Markup Toolbar button, choose Highlight Selection, Text, Note, Shapes or Sketch, and mark the page, then save the file. To add comments from any browser, including on Windows, use PDF Annotator, which keeps your file on your device. Page: https://pdfinish.com/blog/how-to-annotate-a-pdf-on-mac Last updated: November 2, 2026 By PDFinish editorial team. Published November 2, 2026. You have a contract, a study guide or a draft report as a PDF, and you want to mark it up. Highlight a line, leave a note, circle a number. Your Mac can do this without installing anything, and so can your browser. This guide shows both, and says which one fits which job. For the browser route, open [PDF Annotator](https://pdfinish.com/annotate-pdf). It highlights, underlines, strikes out and adds notes, text boxes and drawings. The Mac steps below use Preview, the app that opens PDFs by default. ## How do I annotate a PDF in Preview on a Mac? Open the PDF in Preview, show the Markup toolbar, pick a tool and mark the page. These steps follow Apple's guide, [Annotate a PDF in Preview on Mac](https://support.apple.com/guide/preview/annotate-a-pdf-prvw11580/mac), which we read on November 2, 2026. Menus change a little between macOS versions, so if yours looks different, check Apple's page. 1. Open the PDF in Preview. 2. If the Markup toolbar is not showing, click the Show Markup Toolbar button. 3. To highlight, select the words, then click Highlight Selection. 4. To add words of your own, click Text, type, then drag the text box where you want it. 5. To leave a comment, click Note. 6. For circles, arrows or freehand marks, use Shapes or Sketch. Apple describes Sketch as drawing a shape with a single stroke. 7. Save the file. Apple says File, then Save, or File, then Export, or File, then Export to PDF all keep your annotations editable later. Apple also notes that you can Control-click a note to choose its color. The same guide lists Underline and Strike out text, and a Sign button if the file needs your signature too. For signing on its own, see [how to sign a PDF without printing it](https://pdfinish.com/blog/how-to-sign-a-pdf-without-printing). ## How do I annotate a PDF in my browser? Add the file to PDF Annotator, select words and choose Highlight, Underline or Strike out, add notes, text boxes or drawings, then press Save annotated PDF. It works on a Mac, a Windows PC or a phone, and your file stays on your device. 1. Add your PDF. Drop it onto the tool or choose it from your device. It opens in your browser straight away. 2. Mark the page. Select words and choose Highlight, Underline or Strike out. Press Note, Text box or Draw and click the page to add one. Pick a color for each mark. 3. Check the comments list. Every comment appears in a list with its page number. Click one to jump to it, and edit or delete it before you save. 4. Press Save annotated PDF and download the copy. Your original file is not changed. A worked example: a freelancer gets a client contract and wants to ask for 14 days to pay instead of 30. They highlight the payment terms, add a note that says so, and save. The client opens the file and sees the highlight and the note on that page. ## Which method should I use? Both do the job. The choice depends on where you are and what you do next. - Preview fits a quick mark on one file when you are at your Mac. It is already installed, so there is nothing to open in a browser. - PDF Annotator fits when you want every comment in one list with its page number, when you move between a Mac, a Windows PC and a phone, or when you want the choice to flatten the marks. - Either way, check the saved copy before you send it. Open it, scroll through and look at each page you marked. PDFinish saves highlights, underlines, strike-outs, notes, text boxes and drawings as standard PDF annotations, the same kind other PDF apps make. Preview and browsers such as Chrome show them. Apps differ a little in how they draw the comment pop-ups. ## What does flattening do to my marks? Flattening locks your marks into the page, so nobody can edit or delete them. Keep an editable copy too, because a flattened copy cannot be changed or replied to. Flatten only the copy you send when you want the marks to look the same everywhere. See [what a flattened PDF is](https://pdfinish.com/blog/what-is-a-flattened-pdf-document) for the full picture, or use [Flatten PDF](https://pdfinish.com/flatten-pdf) on a finished copy. ## Can I remove annotations later? Yes, if you kept the editable copy. Open it in PDF Annotator again. The marks already in the file show in the list, and you can delete them and save a clean copy. Marks you flattened cannot be removed, so keep the editable version. ## Common problems and fixes - The highlight tool selects nothing. The page may be a scan, which is a picture with no text to select. Use Note, Text box or Draw instead. - The other person cannot see your marks. Ask them to open the file in a PDF app that shows comments, such as Preview or a browser, and check you did not send a different copy. - A mark covers a printed word. Move or resize it in the editor before you save, then zoom in to check. - The file is too big to email. Use [Compress PDF](https://pdfinish.com/compress-pdf), and read [why your PDF is so big](https://pdfinish.com/blog/why-is-my-pdf-so-big) first, because the strongest setting turns text into pictures. Look at your marks afterwards. - You only need to trim the page, not mark it. See [how to crop a PDF on a Mac](https://pdfinish.com/blog/how-to-crop-a-pdf-on-mac). ## Where does your file go? Contracts and drafts often hold names, prices and addresses. PDF Annotator opens and marks up your file in your browser tab and saves the copy there too, so the file is not sent to our servers. Whatever tool you use, it is worth checking how it handles your files. ## A short checklist - Keep your original file. - Mark the page, then read the comments list from top to bottom. - Save an editable copy, and flatten only the copy you send. - Open the saved file and look at each marked page. 2 free uses in total, no account needed. Free files can be up to 50 MB, and Pro allows up to 500 MB. ## Sources - Apple Support, [Annotate a PDF in Preview on Mac](https://support.apple.com/guide/preview/annotate-a-pdf-prvw11580/mac), read November 2, 2026. - PDFinish's own [PDF Annotator](https://pdfinish.com/annotate-pdf) page, for the tools, the comments list and the flatten option, as of November 2026. ## Common questions ### How do I annotate a PDF on a Mac for free? Open the PDF in Preview, click Show Markup Toolbar, choose Highlight Selection, Text, Note, Shapes or Sketch, mark the page and save. You can also use PDF Annotator in a browser, which is free to start. ### How do I highlight text in a PDF on a Mac? Open the PDF in Preview, show the Markup toolbar, select the words and click Highlight Selection. In PDF Annotator, select the words and choose Highlight. ### How do I add a note or comment to a PDF on a Mac? In Preview, click Note in the Markup toolbar and click the page. In PDF Annotator, press Note, click the page and type your comment. Every comment shows in a list with its page number. ### How do I save a PDF in Preview so I can edit the annotations later? According to Apple's guide, as of November 2026, choose File, then Save, File, then Export, or File, then Export to PDF. Each keeps your annotations editable later. ### Will other people see my annotations? Yes. Marks made in PDF Annotator are saved as standard PDF annotations, so Preview and browsers show them. If you flatten the copy, the marks become part of the page and cannot be edited. ### Is my file uploaded when I annotate a PDF in PDFinish? No. Your PDF is opened and marked up in your browser, and the copy is saved there too. The file is not sent to our servers. ## Try it - [PDF Annotator](https://pdfinish.com/annotate-pdf): Highlight text, add comments, notes and drawings to a PDF. - [Flatten PDF](https://pdfinish.com/flatten-pdf): Lock form fields and comments into the page, or turn pages into images. - [Sign PDF](https://pdfinish.com/sign-pdf): Draw or type your signature and place it on the page. This article is general information, not legal or tax advice.