BlogGuide8 October 20267 min read

How to annotate a screenshot on your Mac

A screenshot rarely explains itself. Someone needs to know which button to press, what changed, or where the error is, and you'd rather not send your email address along with it. Here's how to mark up a screenshot on a Mac with the tools you already have, and a faster way that starts right from the screenshot preview.

Mac screenshot shortcuts

Every way of annotating starts with a screenshot. These work on every recent Mac:

Screenshots are saved to your Desktop unless you choose another folder in ⌘⇧5 › Options.

1. Annotate with Markup (built in)

Take a screenshot with ⌘⇧3, ⌘⇧4, or ⌘⇧5, and click the thumbnail that appears in the corner of the screen before it slides away. macOS opens it in Markup, where you can sketch, draw shapes and arrows, add text, crop, and rotate. Click Done to save.

• Add an arrow: click the Shapes button, choose the arrow, then drag its ends into place.
• Add text: click the Text button, type, and use the font button for size and colour.
• Circle something: use the Sketch tool; a rough circle snaps into a neat oval.
• Crop: click the Crop button and drag the corners.

It's quick and always there. What it doesn't have: a way to blur private details, numbered steps, or a background to make the picture look good in a post or a slide.

2. Annotate in Preview (built in)

Open any screenshot in Preview and click the Markup button (the pen tip) in the toolbar. You get the same shapes, text, and lines, plus colour, line, and font controls, and Tools › Adjust Size to make the image smaller before you send it. To crop, drag over the part to keep and choose Tools › Crop (⌘K). Preview works for any image, not just the screenshot you just took.

To hide something, the usual trick is to draw a rectangle over it and fill it with a solid colour. That works, but it looks heavy-handed, and if you save as PDF the shape can sometimes be moved off what it hides. Flatten to an image (PNG or JPEG) before you share.

3. Edit from the NotchDude screenshot preview

If you use NotchDude, every screenshot you save already shows a preview at the bottom right of the screen, with four quick actions. (Disclosure: I make NotchDude.) Hover it and choose Edit to open the screenshot editor, which is a Pro feature.

The editor opens sized to your screenshot, with every tool named along the top:

• Point things out: arrows, rectangles, ovals, and a pen for freehand lines, in eight colours and three line weights.
• Explain: text in any font size, a highlighter for a line of text, and Steps that number themselves 1, 2, 3 as you click.
• Hide and focus: Blur passwords, email addresses, and names, or use Spotlight to dim everything except the part that matters.
• Crop to the part worth showing.

Each tool has a one-letter shortcut, such as A for Arrow, T for Text, and B for Blur. Whatever you draw stays selected, so you can drag its handles to resize it, press ⌘= or ⌘- to make it bigger or smaller, ⌘D to duplicate it, or nudge it with the arrow keys. ⌘Z undoes, and Esc only deselects, so you never lose your work by accident.

Add a background for posts and slides

Screenshots shared on social media, in docs, or on a slide look better with some space around them. In the sidebar, choose a gradient or a solid colour, then set the padding, how round the corners are, and the shadow. Pick a shape (Auto, 1:1, 4:3, 16:9, or 9:16) to fit a post, a slide, or a story. NotchDude remembers the last background you used.

Screenshot editor shortcuts

Press a letter with the picture focused to switch tools, or hover a tool to see its letter.

Save, copy, or drag it out

• Save & Close (⌘S) saves over the screenshot, in its own format and resolution.
• Save Copy… saves a new PNG, JPEG, or HEIC file and leaves the original as it was.
• Copy (⌘C) puts the edited picture on the clipboard, ready to paste into Slack, an email, or a doc.
• Drag drops it straight into another app.

Changed your mind? Revert to Original is at the bottom of the sidebar.

Set up the screenshot preview

1. In Settings › Files, make sure Screenshot thumbnail is on, and pick its four actions. With screenshots added to the shelf automatically, they start as Copy, Edit, More, and AirDrop; otherwise Keep takes Edit's place, and Edit is under More.
2. To see only NotchDude's preview, press ⌘⇧5, click Options, and untick Show Floating Thumbnail.
3. Take a screenshot. The preview appears at the bottom right of the screen you're using, above your other windows.

Not seeing it? The guide covers the usual causes, like screenshots copied to the clipboard instead of saved.

Which should you use?

• A quick circle or arrow: click the macOS floating thumbnail and use Markup.
• An older screenshot or any image: Preview.
• Blur, numbered steps, or a background for sharing: the NotchDude screenshot editor, right from the preview.

FAQ