10 Essential Tips Every Mac User Should Know About Preview

As a Mac user, you‘re probably familiar with Preview, the versatile built-in app for viewing images and PDFs. But many people write off Preview as nothing more than a basic file viewer without realizing how powerful it really is. Look beyond the surface and you‘ll find an impressive suite of tools for working with images, PDFs, and other documents.

To help you get the most out of this underrated app, here are 10 essential Preview tips every Mac user should know. Master these and you‘ll be well on your way to becoming a Preview power user!

1. Navigate Multi-Page Documents with the Sidebar

When you open a multi-page document like a PDF in Preview, you can easily jump between pages or get an overview using the sidebar. To open it, click the Sidebar button on the toolbar (it looks like a rectangle with lines) and choose one of the following from the menu:

• Thumbnails: Displays miniature previews of each page. Click one to jump to that page.
• Table of Contents: Shows any bookmarks or a linked table of contents. Click an entry to go to that section.
• Highlights and Notes: Lists any highlighted text or notes you‘ve added to the document (more on that later).
• Bookmarks: Displays any bookmarks you‘ve added. Click one to hop to that page.
• Contact Sheet: Lays out thumbnail previews of the pages in a grid.

Use the sidebar to get a bird‘s eye view of your document and navigate through it quickly. You can even rearrange PDF pages by dragging the thumbnails into a different order!

2. Annotate PDFs and Images with the Markup Toolbar

Preview packs a full set of annotation tools for marking up images and PDFs. To access them, click the toolbox Show Markup Toolbar button or press Command+Shift+A.

Here are a few handy things you can do with the markup toolbar:

• Draw shapes: Use the rectangle, oval, line, arrow and other shape tools to draw on your document. Click the shape button and hold to reveal additional related tools.
• Add text: Click the Text button to type text on top of the document. Choose the font, size, color and alignment in the pop-up toolbar.
• Sketch freehand: Use the Sketch tool (pencil icon) to draw or write freehand using your mouse or trackpad. Press harder for thicker lines.
• Highlight text: In a PDF, select some text and click the highlight button (marker icon) to apply a colored highlight over it, like a highlighter marker. Click the arrow next to the icon to choose a different color.
• Redact content: Hide sensitive information using the redact button, which draws a black box over the selected area. The original content is permanently removed if you save the redacted file.
• Add notes: Click the Note button (square with lines) and drag to create a virtual sticky note on the page. Double-click it to open and type your note.
• Sign documents: Click the signature button (signing line) to add a saved signature or create a new one. Signatures are drawn using your trackpad or camera.

The markup toolbar puts a full set of PDF and image annotation tools at your fingertips. Even if you‘ve never used Preview for much more than viewing, give them a try – you may be surprised how much you can do without needing another app!

3. Magnify with the Loupe

Need a closer look at the details in an image or document? The Loupe tool acts as a magnifying glass that enlarges the area under your pointer. To turn it on, press the ` key (to the left of the 1 key) or click the right side of the search bar and choose Show Magnifier.

Now just move your pointer around the document and the loupe will show an enlarged view centered on it. This is handy for taking a closer peek at small details without zooming the entire image.

4. Crop Images with Selection Tools

Trimming unwanted parts out of an image is a snap in Preview. Follow these steps:

1. Click the Show Markup Toolbar button if the annotation tools aren‘t visible.
2. Select the Rectangular Selection tool (dotted rectangle icon). You can also choose Elliptical Selection (circle) or Lasso (freehand).
3. Drag a selection box around the part of the image you want to keep. Drag the blue handles to adjust the selection if needed.
4. Press Command+K or choose Crop from the Tools menu to discard the rest of the image and keep only the selected area.

Voila – your image is trimmed down to just the part you selected. Remember, cropping always cuts away the non-selected area, so choose your selection carefully!

5. Resize Images to Custom Dimensions

In addition to cropping, Preview offers an easy way to resize images to specific pixel dimensions or percentages:

1. Open the Tools menu and select Adjust Size.
2. Enter a new Width and Height in pixels. The image will scale proportionally by default, but you can uncheck "Scale proportionally" to set each dimension separately.
3. Alternatively, click the dropdown menus and choose Percent to resize by percentage instead of pixels.
4. Click OK to apply the new size.

Resizing images directly in Preview saves you from opening a separate editor. Give it a try next time you need to quickly change an image‘s dimensions or scale it down for sharing online.

6. Rotate and Flip Images

Is your photo upside down or backward? Fix it in a flash with Preview‘s rotation tools:

• Rotate counterclockwise: Click the Rotate button on the toolbar (curved arrow pointing left) or press Command+R.
• Rotate clockwise: Press Option+Command+R.
• Flip horizontal: Go to the Tools menu and select Flip Horizontal.
• Flip vertical: Go to Tools > Flip Vertical.

Each command rotates the image 90 degrees or flips it on the selected axis. To straighten a crooked image, hold Control and click the Rotate button, which will rotate in 1-degree increments for finer adjustments.

7. Adjust Image Colors

While not as advanced as editors like Photoshop, Preview does include some handy color adjustment tools for tweaking your images:

1. Open the Tools menu and select Adjust Color, or press Command+Option+C.
2. In the Adjust Color window, drag the sliders to modify the following properties:
   • Exposure: Makes the image brighter or darker overall.
   • Contrast: Increases or decreases the difference between the light and dark tones.
   • Highlights: Recovers detail in the brightest parts of the image.
   • Shadows: Brings out detail in the darkest areas.
   • Saturation: Makes colors more vivid or subdued.
   • Temperature: Adjusts the overall color balance warmer (yellow/red) or cooler (blue).
   • Tint: Shifts the color balance green or magenta.
   • Sharpness: Enhances edge contrast to make details crisper.
   • Sepia: Applies a sepia tone effect.
3. To remove all adjustments, click the Reset All button at the bottom.

These color adjustments are non-destructive, meaning you can always revert back to the original image as long as you don‘t save the changes. Feel free to experiment with different looks without worrying about ruining your original.

8. Highlight Text in PDFs

Studying a textbook or research paper? Use Preview‘s highlighting tools to mark key passages just like you would with a real highlighter:

1. Select some text in the PDF.
2. Click the Highlight button (marker icon) on the Markup toolbar.
3. To change colors, click the arrow on the Highlight button and pick a new one.

Your highlighted text will also appear under Highlights and Notes in the sidebar, allowing you to quickly see all of your highlights in one place. To remove a highlight, select it and press Delete.

9. Inspect Image Metadata

Digital photos and documents contain additional info about themselves called metadata. To view this in Preview, open the Tools menu and click Show Inspector, or press Command+I.

The Inspector window contains several tabs of metadata:

• General: Basic info like the file name, kind, size, created/modified dates, and resolution.
• More Info: Additional details about the file, which you can edit.
• Exif: For photos, the camera settings and location info embedded by the camera or phone that took the picture.
• IPTC: Standardized metadata used by photographers and publications to store captions, keywords, rights info and other details.
• TIFF: Technical metadata about the file‘s structure, compression and color profile.

Click the tab headers at the top of the Inspector to switch between these different metadata views. You can use the Inspector to check a photo‘s camera settings, see where it was taken, find out who owns an image, or just get more details about any document.

10. Customize the Preview Toolbar

Most of Preview‘s tools are accessible from the menus, but you can also add buttons for your most-used commands directly to the toolbar:

1. Open the View menu and click Customize Toolbar.
2. Drag your desired command icons from the dialog box onto the toolbar.
3. Rearrange the buttons on the toolbar by dragging them left or right.
4. Control-click the toolbar and select Icon Only, Text Only, or Icon and Text to change how the buttons are displayed.
5. Drag the spacer or flexible space buttons into the toolbar to add gaps between groups of buttons.
6. Click Done when you‘ve got the toolbar set up to your liking.

Add buttons for your most-used markup tools, rotate buttons, Adjust Color, Adjust Size, or whatever you find yourself frequently accessing from the menus. Taking a few minutes to set up the toolbar can save you many more minutes over time!

Bonus: Dig Deeper with Preview

These 10 tips are really just the beginning of what you can do with Preview. As you explore the menus and buttons, you‘ll find even more tools for working with images and PDFs, like:

• The Instant Alpha tool (magic wand button) that lets you remove solid-colored backgrounds from images
• Contact Sheet view (Tools > Contact Sheet) for viewing multi-page documents as a grid of thumbnails
• The Edit menu commands for copying, pasting and inserting images into documents
• Export options (File > Export) for converting files to different formats
• The Signature tool for signing PDF forms by drawing your signature on the trackpad

Preview may not have all the bells and whistles of Photoshop, but its built-in tools are more than capable of handling most everyday image and PDF tasks. Get to know them and you may be surprised how much you can accomplish without opening another app.

Thanks for reading, and happy Previewing! Let me know in the comments if you have a favorite Preview tip I didn‘t mention.