Use a spare phone as a second screen

An old iPhone or Android phone makes a handy little extra screen next to your Mac: perfect for Slack, Spotify, a timer or your to-do list. Open a link in the phone's browser and it shows an extra Mac screen sized to the phone.

How to set it up

1. Install SpareScreen on your Mac with the line above. It opens in the menu bar.
2. Allow Screen Recording when macOS asks. That lets SpareScreen show the extra screen on your phone.
3. Open the link in the phone's browser. Click SpareScreen in the menu bar to see the link and its QR code, then open it on the phone. Both need to be on the same Wi-Fi.
4. Click Allow on the Mac. An extra screen appears, shaped exactly like your phone. Drag windows onto it like any monitor.

Turn the phone sideways for a wide strip, or keep it upright for a tall one. The extra screen follows. In SpareScreen's menu, "Text size → Larger" makes everything easier to read on a small screen.

Good to know

• Use Text size → Larger in SpareScreen's menu so things are readable on a small screen.
• Put the phone on a stand and on its charger; a bright screen all day uses a lot of battery.
• Touch control is optional. Turn it on in the SpareScreen menu (it asks for Accessibility permission) to tap, drag, right-click and scroll on the device. Typing still happens on the Mac.
• Everyday work feels instant. Video and fast scrolling are heavier and can stutter on slow Wi-Fi; 5 GHz Wi-Fi helps.
• Streaming services stay black. Netflix, Prime Video and Disney+ block screen capture in every app like this.
• Use Wi-Fi you trust. The picture travels over your local network, never through the internet.

Questions

Can I use an iPhone as a second screen for a Mac?

Yes. Open the link in Safari on the iPhone. There's nothing to install on it.

Isn't a phone too small?

For a full workspace, yes; for chat, music controls, a timer or notes it's ideal. Use Text size → Larger in the menu for easier reading.

What does SpareScreen cost?

It's free for 7 days, then $7.99 once. It's a one-time purchase with no subscription, and one key works on up to 3 Macs.

Which Macs does it work on?

Any Mac running macOS 13 Ventura or later, with Apple Silicon or Intel.

More guides

• Use your iPad as a second monitor for Mac
• Use an Android tablet as a second monitor for your Mac (wireless
• Use an old laptop or Chromebook as a second monitor for your Mac
• Sidecar alternative for iPads Sidecar doesn't support
• Sidecar not working or iPad not supported? Use any device as a Mac second screen
• Duet Display alternative with no subscription
• Luna Display alternative
• spacedesk for Mac? Here's what works on macOS instead
• Wireless second monitor for your MacBook
• Use a Chromebook as a second monitor for your Mac (wireless
• Use an Amazon Fire tablet as a second monitor for your Mac
• Use a Samsung Galaxy Tab as a second monitor for your Mac
• Use a Windows laptop as a second monitor for your Mac
• Add a second monitor to your Mac mini using a tablet or laptop you own
• Use an old iPad as a second monitor for your Mac (iPad Air 2
• Best ways to add a second screen to your Mac

Last updated October 2026.