Turn the Mac you own into the monitor you don't need to buy.

MacDisplay extends your Mac's display to any other Mac running macOS 11 or later. Over Thunderbolt, Ethernet, or Wi-Fi. No hardware, no account, no cloud. 18 megabytes. €29.99 + VAT. Try it free now.

With MacDisplay 3.0, you can also transfer files over Thunderbolt or Ethernet and control another Mac with the same mouse and keyboard.

Download for Mac See how it works
  • macOS 11+
  • 25 MB · notarized
  • Free to try · €29.99 + VAT
Act 01

Plug in the cable.

Thunderbolt, Ethernet, or your local Wi-Fi. MacDisplay prefers the most stable connection — Thunderbolt first, then Ethernet, Wi-Fi last.

Act 02

Two keyboard shortcuts.

⇧ ⌘ E on the source Mac to broadcast, ⇧ ⌘ M on the receiver to accept. The two Macs connect — no menus, no setup wizard, no waiting.

Act 03

Your desktop extends.

More space to work, wherever you are. Drag windows between Macs as if they shared a single graphics card. Independent workspace, native cursor, native resolution.

The problem

Got an iMac you barely use? A MacBook that needs more screen?

01

Most people already own a Mac sitting on a desk at home, half-asleep, doing almost nothing.

02

And the same people, on the move, work all day on a single 13-inch display that's too small for serious work.

03

The second screen is already in the room. You just need the software that connects the two.

How it works

Extend your display in three steps.

01

Download MacDisplay.

A single 25 MB app. Drag it to /Applications or run it from a USB stick. No installer.

02

Open it on both Macs.

Same app, two roles. The source Mac sends its display. The receiver Mac becomes a monitor.

03

Plug in and work.

Thunderbolt cable, Ethernet, or shared Wi-Fi. MacDisplay finds the link. Your desktop extends.

Plug in. Open. Extended.

Why MacDisplay

A Mac-to-Mac second monitor.

MacDisplay is built the way a Mac app should be: local, lightweight, with no dedicated hardware or account, and a one-time license.

01

Zero hardware.

No dongle, no receiver box, no Lightning adapter. Two Macs. One cable. That's it.

02

Zero account, zero cloud.

No sign-up. No tracking. No telemetry. The app does not talk to any server we run.

03

18 megabytes. Runs also from USB.

One file, no installer. Notarized by Apple. Runs from /Applications, the Desktop, or a USB stick.

04

Thunderbolt, Ethernet, Wi-Fi.

MacDisplay prefers the most stable link: Thunderbolt first, Ethernet next, Wi-Fi last. No setup required.

05

LAN-only by design.

Your pixels never leave your network. No cloud relay. GDPR-friendly by design, not by promise.

06

€29.99. Once. Forever.

Buy it once, own it forever. Updates included. No subscription, no in-app purchases, ever.

New in 3.0

Two Macs. More ways to work.

Your files. From one Mac to the other.

Transfer files over Thunderbolt or Ethernet: drag them into the “To send” box or onto the corner panel, and the receiving Mac chooses which folder they land in — even the Desktop.

One mouse. One keyboard. Two Macs.

Move the pointer to the other Mac and keep working with the same keyboard. Each Mac keeps its own apps and files. Share the clipboard too, if you want. Press ⌃⌥⌘ to come back to your own Mac whenever you like.

Together, when you need it.

Keyboard/Mouse and File Transfer can run at the same time. Turning on Extend Display pauses both, and they come back on their own as soon as you stop extending.

QuickMonitor Bonus feature

A USB stick is all you need.

For day-to-day use, MacDisplay just installs on your two Macs. QuickMonitor is the bonus feature for when the receiver Mac isn't yours.

Export a tiny receiver binary onto any USB stick. Plug the stick into any Mac — a friend's, a colleague's, even one at a hotel front desk — double-click, and that Mac becomes your second monitor for the session.

When you unplug, nothing remains. No installer. No background service. No trace.

  • Export from MacDisplay in two clicks.
  • Runs on any Mac with macOS 11 or later.
  • Auto-removes from the host on quit.
Compare

How MacDisplay compares.

Feature Luna Display Duet Display Sidecar / AirPlay (Apple) MacDisplay
Type of solutionHardware dongle + appApp, subscriptionBuilt into macOSApp, one-time purchase
Price¹$89.99 one-time (dongle)from ~$4/month, or lifetime ~$199Included in macOS€29.99 + VAT, one-time
Free trialNo — requires dongle purchase7 days—Free version, never expires
Mac-to-Mac extensionYes, with dongleYes (macOS 12.3+)Sidecar: iPad only · AirPlay: compatible receiversYes, pure software
Extra hardwareDongle requiredNoneNoneNone
SubscriptionNoYes (or lifetime)NoNo
Account requiredYesYesSidecar: same Apple Account · AirPlay: no shared account requiredNone
Older receiver MacsYes, supports older Macs¹Recent macOS required¹AirPlay: support depends on the modelFrom 2014 (macOS 11)
iPad / Windows supportYes (iPad)Yes (iPad & Windows)Yes (iPad)No — Mac ↔ Mac only
Runs from USB stick, no installNoNoNoYes, on any Mac (QuickMonitor)

¹ Vendor-published data from their official websites, July 2026 — may change; check the vendors' sites. In two photographed Ethernet Clock Tests on an M4 Pro MacBook Pro and a 2017 iMac, MacDisplay showed approximate visible offsets of 80 ms and 70 ms. Results vary with hardware, settings and workload. All trademarks belong to their respective owners and are used for identification purposes only. Spotted an inaccuracy? Write to support@macdisplay.it.

Made for

Every Mac, in any situation.

Any Mac from 2014 onwards. New, recent, or vintage. Your daily driver or a backup. Yours, a family member's, a colleague's. If it's a Mac, it can become your screen.

More screen, without buying a monitor.

You're at your desk with the MacBook. You want more space. The iMac next to you becomes your second display in seconds. Then you go back to the MacBook alone whenever you want.

Off-site meeting. One extra screen.

You're at a client's office with your MacBook. Open MacDisplay on the meeting-room Mac: your desktop extends. You present, work, and take notes across two screens. When you leave, nothing remains.

Work anywhere, even away from home.

On a trip, on vacation, at your parents'. You bring the MacBook. You find the second screen on-site: a relative's Mac, or a friend's. A USB stick is enough to turn it into a monitor. Up and running in a minute.

When you need a screen now.

At a coworking space, at university, on a group project. The Mac of the colleague next to you can become your second screen for an afternoon. Same app, same network, double the space. Disconnects when you're done.

Privacy & security

Built LAN-first. Always has been.

MacDisplay is private by nature. It connects two of your Macs and gets out of the way.

  • Cable or LAN only.
    Screen content, files, and control data travel directly between your Macs over the local connection. They never reach a server we operate.
  • Lockdown. Cable only.
    Block MacDisplay from using Wi-Fi and force a Thunderbolt or Ethernet connection. Especially useful on public networks.
  • Control starts with six digits.
    The first time you connect, six digits appear on both screens: you compare them and allow. The control connection is encrypted with AES-256-GCM. Clipboard sharing is up to you.
  • Nothing leaves your network.
    No relay. No proxy. No cloud. If your router is off, MacDisplay still works between Macs on the same cable.
  • No account, no tracking.
    We don't ask for your email. We don't run analytics inside the app. GDPR-friendly by design.
Compatibility

Works with what you already own.

If you bought a Mac in the last decade, MacDisplay will run on it.

Extend Display — source MacmacOS 12.3 or later
Extend Display — receiver MacmacOS 11 or later
ConnectionsThunderbolt 3/4/5 · Gigabit Ethernet · Wi-Fi 5 GHz
App size25 MB · universal binary · notarized by Apple
LanguagesEnglish · Italian (more coming)
Current versionMacDisplay 3.0.3 · last updated 16 October 2026 What changed →
Free version

Free. No expiry date.

Try MacDisplay with no account and no credit card. The free version includes Extend Display, Keyboard/Mouse, and File Transfer, with limits on usage time and file sending.

Shared time

10-minute blocks

Extend Display and Keyboard/Mouse share the same 10-minute blocks. Reconnecting or switching between the two does not restart the block.

Between blocks

60-second cooldown

Once a block is used up, wait 60 seconds before starting the next one.

Per day

60 minutes per day

One daily allowance, shared between Extend Display and Keyboard/Mouse. It resets at midnight.

File Transfer

2 GB of files per day

Send up to 2 GB per day, with a maximum of 2 GB per transfer. This resets at midnight too.

Limits apply on one side only.
Only the Mac extending its display, controlling another Mac, or sending files uses the allowance. The Mac receiving the display, being controlled, or receiving files is always unlimited — even in the free version.

With the full license

Every limit, gone.

One €29.99 + VAT license removes the free-version limits for Extend Display, Keyboard/Mouse, and File Transfer.

  • No time or transfer limits

    No 10-minute blocks, no 60-second cooldown, no daily cap. And no limit on the gigabytes you send.

  • Up to 3 personal Macs

    Activate your license on the Macs you use to extend the display, control another Mac, or send files.

  • No license on the receiving Mac

    Receiving the display, being controlled, and receiving files are unlimited even in the free version.

Get MacDisplay — €29.99 + VAT · one license, forever
Reviews

What early users say.

5.0 — average of all 6 reviews on Trustpilot Read all reviews on Trustpilot →
★★★★★

This is THE 'use an old Mac as a display' solution

“As an owner of both a Mac Studio (2023) and an iMac (2019), I strongly wanted to get use of the older Mac as an 2nd display for the newer one. For some time now, I've used a competitor's technology but have never been quite satisfied with the quality of the displayed content or the speed of response. Enter MacDisplay. A software solution that just works, and works very well. Responsive and clear. And the Support Staff is incredible, promptly responding to an issue (I created) with expert help and additional suggestions for best performance. The app price? Wow! Distinctly affordable. This is THE 'use an old Mac as a display' solution. Kudos, MacDisplay.”

Harold Toups · United States · 10 September 2026 · Review on Trustpilot

★★★★★

A great way to use an iMac as a second monitor

“I tried MacDisplay with a 2020 MacBook and a 2017 iMac 5K connected over Thunderbolt. Latency is very low and image quality is excellent. For productivity and everyday use, even for long stretches, I had no problems. I wouldn't recommend the Wi-Fi connection unless your network is really good. A great way to turn an iMac into a second monitor.”

Giorgia · 14 July 2026 · Review on Trustpilot, translated from Italian

★★★★★

A great way to use two MacBooks as a dual screen

“I tried the app connecting my 2021 MacBook to my boyfriend's, and it worked really well for me. It's very handy when we are travelling or away from home, because I can use the second MacBook as an extra screen to work and study more comfortably. Simple, practical and genuinely useful. I recommend it to anyone who wants to work with two screens without carrying an external monitor.”

Ludovica · 5 July 2026 · Review on Trustpilot, translated from Italian

★★★★★

A great way to use a Mac as a second screen

“I tried MacDisplay to turn the screen of an old Mac into a second monitor and the experience was really positive. Setup is simple and intuitive, even for someone who isn't particularly expert, and in a few steps I managed to connect the screen. Support was really fast and clear.”

Sara · 22 July 2026 · Review on Trustpilot, translated from Italian

★★★★★

A really great experience

“A really great experience! I connected my MacBook to my old iMac without any trouble and used it as a second screen. Simple setup, stable connection, and everything worked right away. Highly recommended!”

Tommaso · 8 August 2026 · Review on Trustpilot, translated from Italian

★★★★★

A friend recommended it, and I'm really glad I bought it

“A friend recommended MacDisplay and, having tried it, I have to say I'm really happy with the purchase. I've been using it for over two weeks now to turn my old 2018 iMac into a second screen for my MacBook Pro. I chose to connect the two over Ethernet, since I already had the cable and the adapter, so I didn't need to buy a Thunderbolt cable. I use it mainly for work and for what I need it works really well. The connection is stable, and being able to bring an old iMac back to life as a second monitor was a very convenient solution that saved me from buying another screen. Something else I particularly appreciated is the support: every time I needed information or a hand with some small problem, I always got quick and helpful replies. I would definitely recommend it.”

Ilaria · 20 August 2026 · Review on Trustpilot, translated from Italian

Reviews are collected and moderated on Trustpilot, an independent platform. Quotes are reproduced faithfully.

Pricing

One price. Once. Forever.

€29.99 + VAT

Price excludes VAT. Local VAT applied automatically at checkout.

  • Extend Display, Keyboard/Mouse, and File Transfer without the free-version limits
  • All current and future updates
  • QuickMonitor USB export
  • Use on up to 3 personal Macs
  • Email support from a real person
Buy now Try it free

Free to download and try. Secure payment through Stripe.

FAQ

Questions, answered.

If something isn't covered here, email support@macdisplay.it.

Can I use my old iMac as a second display for my MacBook?
Yes — that's exactly what MacDisplay is for. Install the app on both Macs, connect them with a Thunderbolt or Ethernet cable (or use Wi-Fi), press the keyboard shortcut, and your MacBook's desktop extends onto the iMac. It works on iMacs from 2014 onwards and MacBooks from late 2013, with macOS 11 or later on the receiving Mac — including iMacs that never had, or lost, Target Display Mode.
Is there an alternative to Target Display Mode?
Yes. Apple removed Target Display Mode after the 2014 iMacs and never brought it back — modern macOS versions don't support it at all. AirPlay to Mac has specific hardware, software, and receiver-setting requirements. MacDisplay is a pure-software alternative: it turns iMacs and other Macs (macOS 11+) into a real extended display over Thunderbolt, Ethernet, or Wi-Fi — no dongle, no subscription.
Do I need a dongle or a subscription?
Neither. MacDisplay is 100% software — no hardware dongle to buy and carry. And it's a one-time €29.99 license, not a subscription: pay once, use it forever, updates included.
My Mac only has Thunderbolt 2 — will it work?
Yes. For Macs with Thunderbolt 2, use Ethernet for a wired connection. You can also use Wi-Fi for Extend Display. We have not yet certified Apple's Thunderbolt 3 to Thunderbolt 2 adapter.
Does MacDisplay need an internet connection?
No. MacDisplay only needs the two Macs to be able to see each other — directly via a Thunderbolt or Ethernet cable, or on the same local Wi-Fi. Your internet connection can be off entirely and it still works.
How is this different from AirPlay or Sidecar?
AirPlay is Apple's option for sharing or extending a screen to compatible receivers. Sidecar turns an iPad into a second display. MacDisplay turns another Mac — typically an iMac or older MacBook you already own — into a true extended second display, with independent workspace, full resolution, and a real cursor.
Which Macs are supported?
For Extend Display: macOS 12.3 or later on the source Mac and macOS 11 or later on the receiver. Keyboard/Mouse and File Transfer work from macOS 11 on both Macs; Keyboard/Mouse also needs Accessibility permission on both. MacDisplay is a universal binary for Apple Silicon and Intel.
Do I need any special hardware?
No. The app uses the cables and ports you already have. Thunderbolt and Ethernet are the most consistent wired options; Wi-Fi 5 GHz works for many desk-bound workloads.
What is QuickMonitor exactly?
QuickMonitor is a feature inside MacDisplay that exports a small standalone receiver onto a USB stick. You can plug that stick into any compatible Mac, double-click the binary, and that Mac instantly becomes a second monitor — without installing anything, without an account, and with no trace left behind when you unplug.
Does MacDisplay mirror the screen or create an extended desktop?
MacDisplay creates a true extended desktop: the receiver Mac adds an independent workspace, and you can drag windows and apps between the two screens. It is not simple mirroring.
Can I watch Netflix or Prime Video on the extended display?
No, and it isn't our choice: macOS blacks out protected video on any shared screen — the same happens with QuickTime screen recording or Zoom screen sharing. But there's a better way: with MacDisplay the second screen is a real Mac, not a passive panel — so open the film on that Mac and drive it with the first Mac's mouse and keyboard. The film plays on one screen, you work on the other, and playback is native, at full quality. Everything else works on the extended display: YouTube, local files, VLC, video calls, video editing.
Can I control a Mac while transferring files?
Yes. Keyboard/Mouse and File Transfer run together, and each Mac keeps its own apps and files. Turning on Extend Display pauses both — on the same cable they would get in each other's way — and they come back on their own as soon as you stop extending.
Can I block MacDisplay from using Wi-Fi?
Yes. Turn on Lockdown to block MacDisplay from using Wi-Fi and force Thunderbolt or Ethernet. It's especially useful on public networks, when you want MacDisplay to communicate over a cable only. It stays on after you quit and reopen the app.
Does MacDisplay work with Siri, Shortcuts or AI assistants like Claude and ChatGPT?
Yes, from version 3.0.2. With Add to Siri you can say “Hey Siri, become a monitor”, “extend the screen” or “stop the screen” (macOS 12 or later), and the same commands work in Shortcuts. Claude, the ChatGPT app and other MCP apps can connect to MacDisplay to read its status and guide and, with a license, act on your request: you approve each action. Everything is in the Assistants & Voice panel.
What does the full license unlock?
The full license removes the free time and file-sending limits. Activate it on up to 3 personal Macs you use to extend the display, control another Mac, or send files. Macs receiving the display, being controlled, or receiving files do not need a license: those uses are unlimited even in the free version.
Can I try MacDisplay before paying?
Yes, with no account and no credit card. Extend Display and Keyboard/Mouse share 10-minute blocks, with a 60-second cooldown between blocks and a total of 60 minutes per day. File Transfer has 2 GB per day, with a maximum of 2 GB per transfer. Everything resets at midnight. Limits apply only to the Mac extending the display, controlling, or sending files: receiving is always unlimited.
Does the price include VAT?
No, the displayed price excludes VAT. Local VAT is applied automatically at checkout based on your country. For example, an Italian customer will see €29.99 + 22% VAT = €36.59 at checkout.
What about refunds?
30-day refund, handled directly by us. Email support@macdisplay.it with your order ID and we'll process it through Stripe.
Where is my data going?
Screen content, files, and control data travel directly between your Macs over the local connection. We do not run relay servers and we do not collect analytics inside the app. With Lockdown, you can block MacDisplay from using Wi-Fi and use a cable only. MacDisplay sends nothing to us. If you connect an AI assistant, what it reads from MacDisplay goes into your conversation with that assistant's provider; with a local model it stays on your Mac.
News

What's new.

All news
Release 3.0.2 12 October 2026

MacDisplay 3.0.2: AI assistants for Mac and a second screen you can control with Siri

Connect Claude or ChatGPT to MacDisplay, control your second screen with Siri, and decide what each assistant can do.
Guide 12 October 2026

How to use a MacBook as a second monitor for another Mac

Turn a spare MacBook into your Mac's second screen: requirements, a wired connection, and how it differs from Sidecar and AirPlay.