Quick edits to PDFs and images without Photoshop

"Circle where I'm supposed to click" or "mark the error in the document" — you can do it in Preview in under a minute, without opening any graphics editor at all. Most people only know Preview as a PDF and image viewer and have no idea it can also edit. Preview, which comes preinstalled on every Mac, can draw arrows and boxes, add text, and blur sensitive information — more than enough for the vast majority of everyday PDF and image edits.

A typical scenario

A coworker asks which button to click in an app. Without annotation tools, you'd have to describe it in words — "the button in the top right, right next to the gear icon" — and she'd probably still spend a while hunting for it.

With Preview's tools, you take a screenshot, circle exactly that button with a red arrow, and send the image — the confusion disappears completely. It works just as well in reverse, when someone sends you a screenshot with an error message and you type directly into the image with the text tool to tell them what to try next.

How to do it

1. Open the image or PDF in Preview — double-click it, or use Open With.
2. In the menu bar, click the marker-pen icon (Show Markup Toolbar) — this opens the panel with annotation tools.
3. The panel offers arrows, rectangles and other shapes, text boxes, a highlighter, and a tool for blurring or blacking out sensitive information (like an ID number or account number on a scanned document).
4. Draw or type whatever you need — you can fine-tune color, line thickness, and text size for each tool in a small dropdown menu next to its icon.
5. Save your changes with Cmd + S — for PDFs, annotations are embedded directly into the file, so anyone who opens the document will see them, even in a different app.
6. The blur tool is usually found in the panel under a target or magnifying-glass icon — select the area, and the sensitive information is irreversibly obscured before you save.

The best tools

• The built-in Preview with its Markup panel — free, no installation, handles drawing, text, and signatures.
• Screenshot (Cmd+Shift+4) combined with Preview — for quickly marking a specific spot on screen and annotating it immediately.
• The Markup panel right from Quick Look — for images and PDFs, you can open annotation tools straight from a Space-triggered preview, without opening the full app.
• Skitch or similar third-party tools — for users who want faster access to their favorite annotation tools or one-click sharing.
• Built-in annotation tools right inside Mail — for attachments, you can open the Markup panel directly in a new-message window, without saving the file first.

What you get out of it

• Time: explaining something "on the picture" is faster to draw than to describe in words, and the recipient gets it at a glance.
• Clarity: visual markup eliminates the misunderstandings that come from describing a position on screen in words.
• Protection of sensitive data: the blur tool can hide account numbers or ID numbers before you send a document on.
• Independence from other software: for everyday annotations and simple edits, you don't need to install or learn a paid graphics editor.

Pro tip

A great trick for cropping: use the selection tool to mark just the area of the image you want to keep, then press Cmd + K — the image crops exactly to the selected area, with no pixel-counting or separate editor required.