What's the best way to share my friend's Mac screen? I'd like to help with some software problems.

If a friend or relative is struggling with a problem on their iPhone, iPad or Mac, or just want to show you something cool or weird that the device is doing, but you can't be there, screen sharing becomes your best friend. A friend in need with a broken Mac is a friend indeed, and you can earn a lot of brownie points by fixing your friend's Mac remotely.

It's not always possible to pop round and help a friend or family member out, but these days it's easier than ever to help them remotely. A macOS feature called Screen Sharing enables you to help troubleshoot a Mac problem right from the comfort of your own Apple Mac. With Screen Sharing you can view your friend's screen, and highlight the buttons and icons they need to tap to fix it.

In this feature we're going to look at how to fix a friend's Mac remotely from your own Apple Mac computer, as well as how to share screens with a Mac on another Mac, or an iPad or iPhone. Additional reporting by Lucy Hattersley and Keir Thomas

Read next: How to connect a Mac to two monitors | How to remotely access a Mac from an iPad, for free

How to screen share or remote-access a Mac screen: Chrome Remote access

If you're using an iPad (in particular) or an iPhone (if you think you'll be able to make our any detail on the smaller screen) then using remote access to view and control what's on your friend's Mac is a good option. And the best way to remote-access a Mac from an iPad is to use Google's free Chrome Remote Access service, which lets you remotely use Mac programs from an iOS device.

It's quite an involved process to set it up the first time, but easy if you want to do it again in future. You'll need the Google Chrome web browser for Mac, and a Google account. If you haven't got these already, you can download Chrome here and sign up for a Google account here.

How to screen share Mac, iPhone & iPad: Chrome Remote Access

On Mac

Open Chrome and go to Chrome Remote Desktop on the Chrome Webstore. Click Add to Chrome, then Add App. Click Allow, then Continue.

Hit Get Started under My Computers, and select Enable Remote Connections, Accept and Install, then OK.

Double-click the chromeremotedesktop.dmg file in your Downloads folder, then double-click the Chrome Remote Desktop Host.pkg icon that appears in Finder. Click Continue, Install, enter your Admin password and click OK. Click Close.

Return to the Chrome Remote Desktop window and click OK. Enter a memorable pin and click OK.

The Chrome Remote Desktop Host Preferences window will open. Click the lock icon. Enter your Admin password (click OK) and your PIN (click Enable).

Click OK in the Chrome Remote Desktop window. Close the Chrome Remote Desktop window, Chrome Remote Desktop Host Preferences window, and Google Chrome windows.

On iPad/iPhone

On your iPad, you'll need to download the Chrome Remote Desktop app. Open the app, tap Sign In and enter your Google ID, then select the appropriate Mac computer in the My Computers window. Enter the PIN we chose earlier and tap Connect.

There are some other excellent iPad remote-control apps out there, but most of them charge a monthly fee, which is why we return to Chrome Remote Access.

We look at this approach in more detail in a separate article: How to remote access a Mac from an iPad for free

How to screen share or remote-access a Mac screen: Mac Screen Sharing

If you're both on Macs, the easiest way to access and control your friend or colleague's screen is to use the screen-sharing feature built into macOS.

Run a Spotlight search (Cmd-space) and enter 'screen sharing' - it'll offer to autocomplete once you've typed in the first couple of letters. Double-click the icon on the right to launch the feature.

How to screen share or remote-access a Mac screen: Mac Screen Sharing

A dialogue box will appear with a single field, labelled 'Hostname or Apple ID'. Enter your mate's Apple ID. An invitation will be sent to them.

(In fact, if your Contacts file for that person includes the correct email address, you can just type the first couple of letters of their name, and then select them from the autocomplete options presented. Contacts who are set up correctly for this will have their names highlighted in blue.)

Read next: How to set up Family Sharing

How to screen share or remote-access a Mac screen: Screen Sharing

The invitation will appear as a notification on your colleague's Mac; they should click Accept, then select either 'Control my screen' or 'Observe my screen' (depending on whether they want you to be able to see what's going on or actually control their Mac) and then Accept.

How to screen share or remote-access a Mac screen: Mac Screen Sharing

How to screen share or remote-access a Mac screen: Mac Screen Sharing

Your colleague's desktop will appear on your desktop as a window. (If they're using two monitors, as is the case here, this window will be double-width.) If your colleagues selected 'Control my screen', you can actually click on the windows and icons inside Screen Sharing and control the other Mac directly. This enables you to fix any problems of the Mac yourself.

In Control Mode you will find that performance is affected by the speed of both your network, and the other person's internet connection. So you may have to be patient. (By default, Screen Sharing adjusts the quality depending on the performance of the network.)

How to screen share or remote-access a Mac screen: Mac Screen Sharing

You can zoom in and out, and if you wish to upgrade your privileges from observing to controlling, you can click the lefthand option (a cursor inside circles) at the top left of the window, labelled Control. This will send a further request that your colleague can accept or decline. (If this isn't displaying, click View > Show Toolbar in the menu.)

How to screen share or remote-access a Mac screen: Mac Screen Sharing

When you're finished, click on the Screen Sharing icon in either Mac and choose End Screen Sharing.

How to screen share or remote-access a Mac screen: Troubleshoot a friend's Mac in Messages or FaceTime

You can troubleshoot a friend's Mac using the new Screen Sharing feature in Messages and FaceTime. Screen Sharing has been a feature of iCloud, and before that MobileMe, for a number of years. But with the launch of Mac OS X Mavericks, Apple extended this to include your friends. With Screen Sharing you do not remote control the other Mac directly, but you can view the display and highlight parts of the screen while talking your friend through the fix.

In this feature we're going to assume that a friend has just called you up and asked you to help them fix their computer. In our case we've got a friend who's accidentally inverted the colours of the screen, and we need to get them to go into Accessibility Settings and change it back.

Both sign up for Apple ID and iCloud

In order for this to work you both need to sign up for Apple's iCloud and iMessages service. Click on System Preferences > iCloud and make sure you're signed in (if not enter your Apple ID and Password and click Sign In. Click on Create Apple ID if you don't have one. Your friend will also need an Apple ID, and you need to know what it is.

Make sure you're talking to them on the phone or using FaceTime, and ask them to click System Preferences > iCloud and read out the email under their name (it often, but not always, is an iCloud.com email address).

Use Screen Sharing's Observe Mode

How to screen share or remote-access a Mac screen: Activate Screen Sharing

Once you're signed in to iCloud and have your friend's Apple ID you are good to go. Follow these steps.

  1. Open Messages on your Mac. Tell your friend to open the Messages app on their Mac too.
  2. Click New Message and Enter their Apple ID into the To field (you can also click on them in the Messages Sidebar if you have previously been using Messages to chat to them).
  3. Click Details in the top right-hand corner.
  4. Click on the Share Screen icon (it is shaped as two small rectangles).
  5. Choose Ask To Share Screen from the Drop Down Menu.
  6. The other person gets a notification asking to share their screen. Tell them to click Accept. If you are not in their contacts they will also have to click on Accept in a warning screen.
  7. A window appears on your desktop displaying their screen. Meanwhile an icon appears in their Menubar with alert saying "[person] is viewing your screen.
  8. Click on the window (displaying their screen) using your mouse to highlight part of their display with a spotlight circle. This can be used to point out parts of the screen that they need to click on.

Use this highlight while talking to them on the phone, or FaceTime, to guide them through the operating system and show them which buttons to click and menu options to choose.

Read more: How to access a Mac remotely: access files wherever you are

How to screen share or remote-access a Mac screen: Use Observe Mode to highlight parts of the screen

How to screen share or remote-access a Mac screen: View Mac desktop on iPad or iPhone, with VNC Viewer

Accessing a computer on the same network as your iPad, iPhone or iPod touch is usually just a matter of entering the local network IP address or computer name when prompted in the apps discussed below.

However, accessing your computer from outside the home or office is more complicated. You'll need to configure your router so that the relevant ports are passed through to the computer you want to connect to. You'll find guides online. It's also wise to configure a dynamic DNS service so that you can connect via a hostname rather than an IP address, which is prone to changing. Examples of dynamic DNS services include NoIP and DuckDNS, which are free of charge, but how they're configured is again outside the scope of this article. There's many guides available online - just search using your router model number and "dynamic DNS".

Setting up your Mac and iPad for screen sharing

Mac OS X uses the established Virtual Network Computing (VNC) protocol to share a desktop remotely, so any iOS app that supports VNC will work. There are quite a few of these, in fact, but one of the best that also happens to be free is VNC Viewer. It can be found in the App Store but before using it you'll need to configure the Mac you want to connect to: put a tick alongside Screen Sharing in the Sharing component of System Preferences, then click the Computer Settings button and ensure there's NOT a tick alongside either of the two headings you see.

Note the address listed beneath the heading that reads Screen Sharing: On. You'll need it to connect in a moment. It's also a good idea to note your Mac's IP address in case using this address doesn't work - click the Apple menu, hold down Alt (Option on some keyboards), and click System Information. In the window that appears click the Network heading in the list at the left, and look alongside either Wi-Fi or Ethernet at the right depending on which your Mac is using.  

How to screen share or remote-access a Mac screen: VNC Viewer

On the Mac you'll need to note either your computer's name or it's IP address, as highlighted here

Connecting to your Mac (or PC) from iPad or iPhone

On the iOS device open the VNC Viewer app and click the plus icon at the top right. In the dialog box that appears, type the address you discovered in the paragraph above, and in the name field type something memorable and identifiable such as Mac Desktop.

Click Done, and then the Connect button. You'll be warned you're using an unencrypted connection. This is unfortunate but there's no way to avoid it, so tap the Connect link at the top right of the window. You'll then be prompted for the username and password of the Mac account you want to log into. You should type the "short" version of your username - usually your first name, or the first whole word of the longer version of the username.

You'll connect immediately and see a tips panel showing some control tricks. However, in short, the mouse cursor is represented by a small dot and you "shove" it around - push up on the screen, for example, and wherever the mouse cursor happens to be it will also move up. It can take a bit of getting used to. Tapping on the screen is the equivalent of clicking. Use the pinch-expand gesture to zoom in and out of the desktop.

To make a keyboard appear for typing, tap the keyboard icon on the toolbar at the top of the screen. To disconnect from the remote Mac, tap the X icon on the toolbar.

How to screen share or remote-access a Mac screen: VNC Viewer

Using the free VNC Viewer app you can remotely control your Mac's desktop

If you want to connect to a Linux desktop, you can install a VNC server package (just check your distro's package archive), and the same VNC Viewer app can be used to connect as described above.

How to screen share or remote-access a Mac screen: Connect to remote Windows computers via iPad or iPhone

Microsoft has a surprising number of apps available for iOS and one of them is Microsoft Remote Desktop. This lets you remotely connect to the desktop of Windows computers. You'll find it in the App Store and it's free of charge.

In typical Microsoft fashion not all versions of Windows have Remote Desktop compatibility built-in, and it's limited to the Ultimate, Business and Professional editions of XP, 7 and 8. (Although there are hacks to make it work on other versions - just Google.)

Before using Remote Desktop you'll need to ensure it's activated on the Windows computer you want to access. This can be done by clicking Start and typing Allow Remote Access To Your Computer. Then click the entry that appears in the results, and click Allow Connections Only From Computers Running Remote Desktop with Network Level Authentication (More Secure). Then click OK.

How to screen share or remote-access a Mac screen: Connect to remote Windows computers

You'll need to activate Remote Desktop on Windows but it's only available on Ultimate, Business and Professional editions of the OS

You'll also need to know the IP address of the Windows computer. Click Start, then type cmd. In the DOS box that appears, type ipconfig and hit Enter. In the output, look for the line that reads IPv4 Address and make a note. Then close the DOS box.

Start the Microsoft Remote Desktop app on your iOS device and click the plus button in the top right, then select Add PC or Server. In the PC Name field, type the IP address you noted earlier. Tap the User Name field, then tap Add User Account. Now type the username and password of the Windows computer you want to access, and tap Save, and then Save in the parent dialog box. Then tap the icon for your new connection. You'll be asked immediately if you want to accept the security certificate. Tap the switch alongside Don't Ask Me Again and then tap Accept.  

How to screen share or remote-access a Mac screen: Connect to remote Windows computers

Connecting to a remote Windows desktop can be done using the free Microsoft Remote Desktop app

You'll see the remote PC's desktop and your fingertip moves the mouse cursor. To switch to touch controls, as if using a touchscreen PC, tap the IP address toolbar at the top of the screen, and select the option at the bottom right on the sidebars that appear. To bring up a keyboard for typing, tap the keyboard icon in the toolbar at the top of the screen.

To disconnect, tap the toolbar and then tap the X at the left of the thumbnail listing at the left of the screen.

Read next: How to install and run Windows on a Mac

How to screen share iPhone, iPad and Mac: FaceTime

If all of this feels like too much of a hassle, don't forget you can always fall back on the simple option. If you're both using Macs and you want to see what's happening on their screen, why not just get them to start a FaceTime call with you, and then point the camera at the Mac screen?

Obviously this approach doesn't allow you to actually access or control the screen, and if you want to see what's going on in really precise detail it's not the best option. But if they just want to show you something weird, the simplest approach may well be the best.

Read more: How to fix FaceTime problems