Zoom: Apple's Built-in Screen Magnifier

Zoom magnifies what's onscreen with a key command, mouse flick, or a double-tap on an iOS touchscreen. Apple, Inc.

Zoom is a screen magnification app built into the operating system of all Apple Mac OS X and iOS products designed to help make computers more accessible to persons 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.​​

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

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

Zoom on a Mac

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

  • Click the Apple menu and select "System Preferences."
  • In the "System" row, select "Universal Access."
  • Click "On" under the Zoom button.
  • 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 the 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 of, restart, or shut down your machine.

Zoom on the iPad, iPhone, and iPod Touch

Zoom can be especially helpful in enabling visually impaired persons to use mobile devices such as the iPad, iPhone, and iPod touch.

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.

You can enable during your initial device setup using iTunes, or activate it later through the "Settings" icon on the Home screen.

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.

Once Zoom is activated, a double-tap with three fingers magnifies the screen to 200%. To increase magnification to as much as 500%, double-tap and then drag three fingers up or down. If you magnify the screen beyond 200%, 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 rotor -- still work when the screen is magnified.

NOTE: 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.