How to Extend or Mirror Your Desktop on macOS Sequoia

Summary

Learn how to extend or mirror your desktop on macOS Sequoia using System Settings. This guide walks you through connecting, configuring, and customizing multiple displays for a better workspace.

Body

Overview

This article explains how to set up multiple displays on macOS Sequoia, including how to extend your desktop to a second screen or mirror your display.

Applicable Environment

  • Operating System: macOS Sequoia
  • Devices: MacOS laptops and desktop (iMac and Mini) computers with support for external displays
  • Use Case: Those wanting to increase screen space or duplicate their screen to another display

Step-by-Step Instructions

1. Connect the External Display

  • Use a compatible cable (HDMI, USB-C, DisplayPort, etc.) or connect wirelessly via AirTame.
  • Ensure both your Mac and the external display are powered on.

2. Open System Settings

  • Click the  Apple menu in the top-left corner of your screen.
  • Select System Settings from the dropdown menu.

3. Access Display Settings

  • In the left-hand sidebar, click Displays.
  • Your Mac will detect the connected display and show configuration options.

4. Choose Display Mode

To Extend Your Desktop:

  • In the Arrangement tab, drag the display icons to position them relative to each other.
  • This creates an extended workspace across both screens.

To Mirror Your Display:

  • Select the drop-down and then choose Mirror Displays
  • This will duplicate your main screen onto the second display.

5. Adjust Display Preferences (Optional), including changing resolution

  • Click on each display to adjust resolution, refresh rate, and scaling options.
    • If resolution options aren't displayed, click Advanced and then toggle "Show resolutions as list"
    • *Note that for SCSU eclassrooms and conference rooms, 1920x1200 resolution is preferred.  Other resolutions may cause the image to not properly display.
  • You can also set which display is the primary one by dragging the white menu bar to the desired screen.

6. Save and Close

  • Your changes are saved automatically.
  • Simply close the System Settings window when you're done.

 

Details

Details

Article ID: 158253
Created
Fri 8/22/25 10:03 AM
Modified
Fri 8/22/25 2:11 PM