How to annotate screenshots on a Mac
The capture shortcuts worth memorising, the clipboard-first workflow that skips the file entirely, where the built-in Preview and Markup run out, and the extra thing the Mac has: an on-device scan that proposes what to cover.
On a Mac the whole job — capture, cover, point, crop, send — can be done without a file ever existing. Screenshot to the clipboard, paste into an editor, mark it up, copy the result, paste it into the message. That loop takes a few seconds once the shortcuts are muscle memory, and it leaves nothing on your Desktop to clean up later, which matters more than it sounds when the screenshots contain things you did not want lying around.
This page covers the capture shortcuts, that clipboard loop, where the built-in tools genuinely suffice and where they stop, and the one capability that exists on the Mac and not on the phone.
The capture shortcuts worth knowing
- Shift-Command-3: the whole screen.
- Shift-Command-4: drag a region. Hold Space while dragging to move the selection you have already sized; press Escape to cancel.
- Shift-Command-4 then Space: the cursor becomes a camera and you click a single window, captured cleanly with its shadow. Hold Option while clicking to capture it without the shadow, which is what you want when the screenshot is going onto a coloured background.
- Shift-Command-5: the capture panel, with the options that matter — where files are saved, a timer, whether the floating thumbnail appears, and screen recording.
- Add Control to any of the first three to put the capture on the clipboard instead of writing a file. Control-Shift-Command-4 is the single most useful shortcut on this page.
By default a captured file lands on the Desktop as a PNG with a name that includes the date and time. That name is not private: exporting or forwarding it tells the recipient exactly when you took it. If you send screenshots often, either change the save location in the Shift-Command-5 options or stop making files at all and use the clipboard variants.
The clipboard loop
- Control-Shift-Command-4 and drag over the region. Nothing is written to disk.
- Switch to your markup app and paste. The image opens as the thing you are working on.
- Cover anything that should not travel, before you annotate. It is the step that cannot be forgotten, so do it while it is the only step in your head.
- Point at the one thing the image is about, and crop to it if the surrounding context is not doing work.
- Copy the result back to the clipboard and paste it straight into the message, ticket or document. Or export a file if the destination needs one.
The reason to prefer this over the file-based route is not speed, it is hygiene. A screenshot of a bank statement that never became a file cannot be found in Spotlight next March, cannot be swept into a backup, and cannot be attached to the wrong email by autocomplete.
What the built-in tools do, honestly
macOS ships real annotation, free, and for many screenshots it is the correct answer. Click the floating thumbnail after a capture and you get Markup immediately. Or open the image in Preview and show the Markup toolbar: shapes, arrows, lines, freehand sketch with shape recognition, text boxes, a signature, and a colour and line-weight picker. Preview will also crop, rotate and export to another format. Recent macOS versions add a redaction tool for PDFs, which is genuinely useful and is a PDF feature, not an image one.
Where it runs out, for images, is specific and short. There is no pixelation and no blur, so hiding something means an opaque shape. There is no numbered-marker tool, so a five-step how-to image means placing five text boxes and keeping them consistent by hand. Line weights are chosen from a small fixed set, so on a 5K capture even the heaviest option can read thin while the same setting on a small crop looks heavy — you end up adjusting per image. And Preview edits an existing file, which means remembering to Duplicate first if you want the original intact.
None of that is a reason to install anything if you are drawing one arrow. It is a reason to have something else on hand for the screenshot with a customer’s address on it and four steps to explain.
Doing it in Marka, and the thing that is Mac-only
Marka is built for the clipboard loop: paste an image in, or open a file, and copy the finished result out or export it as PNG, JPEG or HEIC with size presets. Every tool has a single unmodified letter on the Mac — v select, c crop, m redact, a arrow, r rectangle, o ellipse, l line, p pen, h highlighter, t text, n number, s sticker — which is what makes the loop fast, because covering and pointing become m-drag, a-drag rather than two trips to a toolbar. Redaction is a brush in three modes: mosaic free, blur and solid part of the one-time Pro purchase. Stroke weight and text size are proportions of the image’s short edge, so a 5K capture and a small crop both get sensible-looking marks without fiddling.
The capability that exists on Mac and not on iPhone or iPad is a sensitive-information scan. It runs Apple’s Vision framework entirely on the device and proposes candidates — phone numbers, email addresses, ID numbers, card-like sequences, faces, URLs — listing them with a checkbox each, with the found numbers themselves masked in the list. It covers only what you tick. It proposes and never acts on its own, and it will miss things: treat it as a second pair of eyes at the end of your own check, not as a substitute for looking. It is part of Pro, as is importing your own PNG stickers, which is also Mac-only in this version.
One thing to know before you rely on it: it is a scratch pad rather than a library — it holds the image you are working on and keeps no copy after you close it, so anything you want to keep must be exported or copied out before you close the window. One purchase covers Mac, iPhone and iPad; Restore Purchases is in Settings on the Mac.
Frequently asked questions
How do I take a screenshot straight to the clipboard on a Mac?
Add Control to the usual shortcut. Control-Shift-Command-4 drags a region to the clipboard, Control-Shift-Command-3 takes the whole screen, and Control-Shift-Command-4 then Space captures a single window. Nothing is written to disk, which is the point when the screenshot contains something you do not want on your Desktop.
Can Preview blur or pixelate part of an image?
No. Preview and the built-in Markup give you shapes, arrows, lines, sketch, text and a signature, and recent macOS versions add a redaction tool for PDFs. For images there is no pixelation and no blur, so hiding something means drawing an opaque shape over it. That is a sound redaction as long as you export a flat file and check it.
How do I capture one window without the drop shadow?
Press Shift-Command-4, then Space to switch to window mode, then hold Option while you click the window. The shadow is removed from the capture, which matters when the screenshot is going onto a coloured background or into a layout where a stray soft edge looks like a mistake.
Does the sensitive-information scan exist on iPhone?
No. It is a Mac-only feature and part of Pro. On iPhone and iPad you cover things yourself with the redaction brush. Even on Mac the scan only proposes candidates with a checkbox each and covers what you tick — it never acts on its own and it will miss things, so it belongs at the end of your own check rather than in place of it.
Is Marka in English on the Mac?
No — the interface is Simplified Chinese in this version, on every platform. Each tool has a single-letter keyboard shortcut and an icon, which is how most non-Chinese-reading users work with it, but you should know before installing rather than after.
Does one purchase cover my Mac and my iPhone?
Yes. It is a single App Store listing with the same bundle identifier across the platforms, so Pro is a one-time Universal Purchase covering Mac, iPhone and iPad at the price your own App Store shows. It is not a subscription. Restore Purchases is in Settings on the Mac and on the Pro screen on iPhone and iPad.
Do it in Marka
Marka is a screenshot markup app for iPhone, iPad and Mac. Brush a mosaic over what should not be seen, point an arrow at what should, number the steps, crop it to the shape you are posting in, and send. Everything is processed on the device — no upload, no account, no analytics, and a 2.4 MB download. Opening, cropping, the mosaic brush and export are free; Pro is a one-time purchase that covers all three platforms.