Zoom: Apple's Built-In Screen Magnifier

Magnifying Glass

Kate Ter Haar/Flickr/CC by 2.0

Zoom is a screen magnification app built into the operating system of all Apple Mac OS X and iOS products. Its intended to make computers more accessible to people who are visually impaired.

Zoom magnifies everything that appears onscreen — including text, graphics, and video — up to 40 times their original size on Mac machines and up to 5 times on iOS devices such as the iPhone and iPod touch.​​

You activate Zoom through keyboard commands, moving the mouse wheel, using trackpad gestures, or double tapping the mobile-device screen with three fingers.

Enlarged images maintain their original clarity and even with motion video, Zoom does not affect system performance.

Zoom on a Mac

To activate Zoom on an iMac, MacBook Air, or MacBook Pro:

  1. Click the Apple menu and select System Preferences.

  2. In the System row, select Universal Access.

  3. Click On under the Zoom button.

  4. Click Options to adjust Zoom settings.

Zoom Settings

With Zoom, you can set a magnification range to prevent images from becoming too large or too small to view when you zoom in.

Use the slider buttons atop the "Options" window to set your desired magnification range.

Zoom also provides three options for how the magnified screen can shift as you type or move the cursor with the mouse or trackball:

  1. The screen can move continuously as you move the cursor

  2. The screen can move only when the cursor reaches the edge of what's visible screen

  3. The screen can move so that the cursor remains in the middle of the screen.

Cursor Magnification

Supplementing Zoom is Mac's ability to magnify the cursor to make it easier to see when you move the mouse.

To enlarge the cursor, click the Mouse tab in the Universal Access window and move the Cursor Size slider to the right.

The cursor will remain until changed, even after you log out, restart, or shut down your machine.

Zoom on the iPad, iPhone, and iPod Touch

Zoom can be especially helpful for visually impaired people who use mobile devices. Though the magnification range (2X to 5X) is smaller than on a Mac machine, Zoom for iOS magnifies the entire screen and works seamlessly with any application.

Zoom can make it easier to read email, type on a small keypad, purchase apps, and manage settings.

Enable it during your initial device setup using iTunes, or activate it later through the Settings app. To activate Zoom, press Settings > General > Accessibility > Zoom.

On the Zoom screen, touch and slide the white Off button (beside the word "Zoom") to the right. Once in the On position, the button turns blue.

After Zoom is activated, a double-tap with three fingers magnifies the screen to 200 percent. To increase magnification to as much as 500 percent, double-tap and then drag three fingers up or down. If you magnify the screen beyond 200 percent, Zoom automatically returns to that magnification level the next time you zoom in.

Once zoomed in, drag or flick with three fingers to move around the screen. Once you start dragging, you can use just one finger.

All of the standard iOS gestures — flick, pinch, tap, and rotate — still work when the screen is magnified.

You cannot use Zoom and VoiceOver screen reader at the same time. And if you use a wireless keyboard to control your iOS device, the enlarged image follows the insertion point, keeping it in the center of the display.