Use Your Phone as a Second Monitor for Your PC
Australians working from home have made peace with smaller living spaces, whether that's a unit in Sydney's Inner West, a townhouse in Brisbane, or a converted verandah in Adelaide. Desk space is often the first casualty, which is why so many people now point an old Android or iPhone at the back of their laptop and use it as a portable second screen. The trick is knowing which method to use, which app to trust, and what trade-offs you are willing to accept.
This guide walks through the built-in options, the dedicated apps that genuinely work, and the settings that make a noticeable difference in latency and battery life. It is written for everyday Australian setups, where NBN connections vary from suburb to suburb and where a second screen often needs to be packed away at the end of the day.
Why a Phone Doubles as a Useful Second Display
A second monitor does not have to be a 27-inch panel. For most office tasks, a six-inch screen beside your laptop is enough to keep Slack, email, or a reference document visible. Australian knowledge workers increasingly treat this as an ergonomic home office setup extension rather than a gimmick, particularly those whose commute has been replaced by a short walk from the kitchen.
The benefit is real. Studies in office ergonomics repeatedly find that an extra screen reduces context-switching and keeps primary tasks in full view. If you are reading a long brief while writing a response, or watching a meeting transcript while taking notes, even a small auxiliary display removes the constant Alt-Tab friction. A phone sitting in a stand on a bookshelf does that job, and it costs nothing if you already own the device.
The Tools Built Into Your Devices
Before installing anything, check what your hardware already offers. Samsung Galaxy owners can use DeX in screen-mirroring mode, which streams a clean Windows or macOS desktop to the phone over USB or Wi-Fi. Microsoft includes a "Connect" app on Windows 10 and 11 that supports Miracast, and most Android phones respond to this natively without extra software.
Apple users have fewer options. Sidecar is locked to iPad, not iPhone, so an iPhone cannot officially act as a Mac monitor without help. AirPlay mirroring works for presentations but introduces too much lag for a daily-driver second screen. macOS users will need a third-party app, which is where the next section earns its place.
Dedicated Apps That Do the Job Well
When built-in tools fall short, a small group of paid and free apps fills the gap. Spacedesk remains the most popular option because it works on Windows, runs on older Android phones, and supports touch input back to the PC. Splashtop Wired XDisplay is the choice for low-latency work over USB, while SuperDisplay and Duet Display target users who want smoother animations and pay for the privilege.
A short overview of the most common choices:
| App | PC Host | Phone Client | Connection | Free Tier |
|---|---|---|---|---|
| Spacedesk | Windows | Android, iOS | Wi-Fi, USB | Yes (with limits) |
| Splashtop Wired XDisplay | Windows, macOS | Android, iOS | USB | Yes (with limits) |
| SuperDisplay | Windows | Android | USB, Wi-Fi | No |
| Duet Display | Windows, macOS | Android, iOS | USB, Wi-Fi | No |
| LetsView | Windows, macOS | Android, iOS | Wi-Fi | Yes |
For Australian users, the Wi-Fi versus USB choice often comes down to NBN reliability in the home. A stable 50 Mbps plan is usually enough for a 1080p stream, but USB avoids the network entirely and is the safer pick in busy apartment blocks where 2.4 GHz channels are crowded.
Wired Versus Wireless Connections
Wireless setups are more convenient. There is no cable to find, and you can move the phone around the desk. The cost is latency, which creeps up whenever the Wi-Fi signal weakens or another device starts streaming. In a Melbourne share house with three Netflix streams running, a wireless second monitor can become unusable during evening hours.
A wired connection through a good USB-C cable removes that variable. Just as the latest generation of cheaper EV batteries is making electric vehicles more practical, modern USB-C standards have made wired phone-to-PC streaming fast enough that most users cannot tell the difference from a dedicated monitor. The trade-off is mobility: the phone must stay within cable reach, and you will need a stand or a clip to keep it upright.
Setting Up on Windows and macOS
On Windows, install the host app on your PC and the client app on your phone from the Play Store or App Store. Both must be on the same Wi-Fi network, or joined over USB. The host usually appears in your display settings as a second monitor, and you can choose to extend or mirror the desktop. Resolution and orientation can be tuned from the Windows display panel.
On macOS, the process is similar for Duet Display and Splashtop. After installing both ends and granting screen-recording permission in System Settings, the iPhone appears in Display settings as an extended display. If you are repurposing an older handset, you may need to reset a Jio phone or a similar entry-level device to clear out background apps that hog memory and slow streaming.
Getting the Best Resolution and Lowest Latency
Once the connection is stable, spend ten minutes tuning the experience. Match the phone's resolution to the streamed output to avoid scaling blur. Drop the frame rate to 30 fps if you only need static documents, and bump it back up for video. On the phone itself, switch to aeroplane mode with Wi-Fi only on, which stops background notifications from chewing through the battery.
A simple test is to drag a window between monitors. If the cursor jumps smoothly and video plays without stutter, the setup is good enough for daily work. If it stutters, switch from Wi-Fi to USB, lower the resolution, or close other network-heavy apps. With these small adjustments, an old phone becomes a reliable second display that travels in your bag and disappears when the workday ends.
For most Australians, the sweet spot is a wired Spacedesk or Splashtop setup with a phone clipped to a stand behind the laptop. It costs nothing beyond a short USB-C cable, takes about ten minutes to configure, and turns hardware that would otherwise sit in a drawer into a daily productivity tool. Once you get used to having a second screen, going back to a single display feels cramped in a way you did not notice before.