Accessing a remote computer from a mobile device

Published on 18 May 2023 by Andrew Owen (4 minutes)

Since 2018, I’ve been using an iPad Pro as my main personal computer (besides my work laptop). It’s great for all my creative work. But every so often I need to run something that’s not supported on iPadOS. So I bought the lowest spec Mac mini available at the time (a 2020 M1 with 8 GB of RAM and a 256 GB SSD). I use my work laptop in a desktop configuration (with an external mouse, keyboard and monitor), and I prefer not to have to swap the USB and HDMI cables over. So the simple option is to use remote desktop software. Microsoft offers its own guest client, but it can only connect to hosts running the Pro version of Windows. For everything else, there’s Chrome Remote Desktop (CRD).

Currently, CRD’s host support includes ChromeOS, Linux, macOS 10.13 or higher and Windows 10 or higher. There are client apps for Android and iOS. For everything else, you can use your web browser (although you may have the option to download an app). With some browsers, such as Safari, CRD will warn you that it needs the latest web technologies. But it won’t actually prevent you from using the service.

While the sessions are encrypted, anyone who has physical access to the remote machine will be able to see what you’re doing on the screen. There is a workaround for this called curtain mode, but it requires some command line steps on macOS and editing the registry on Windows. The obfuscation approach is to run headless (without a monitor). In recent versions of macOS that presents another problem which is that unless a monitor is connected, the GPU is inactive and you can’t resize the display. The workaround for that is to plug in an HDMI ghost. This fools the machine into thinking it’s connected to a monitor, enables the GPU and gives you control over the screen resolution on the guest.

Set up remote access to your computer

• For ChromeOS, you can get the CRD app from the Chrome Web Store.
• For macOS and Windows:
  1. In your browser, navigate to https://remotedesktop.google.com/access.
  2. Under Set up Remote Access, click Download and follow the instructions.
• For Intel 64-bit Debian based Linux, download the CRD package and then follow the steps for macOS and Windows. Optionally, you may want to customize your virtual desktop session.

When you’ve set up the computer, you’ll see it listed in the Remote Access tab. Here you can remove it, or change the computer name and PIN.

Access your computer

1. With an Android or iOS device, get the CRD app from Google Play or the Apple App Store. With a laptop, in your browser, navigate to https://remotedesktop.google.com/access.
2. Open the app and tap the computer you want to access. If it’s dimmed, it’s unavailable.
3. Enter the required PIN.
4. Click the arrow to connect.

You can configure the app from the hamburger icon (☰) and most of the items are self-explanatory. The app has two different modes. In Touch mode is similar to how you normally interact with your phone or tablet. Trackpad mode provides a virtual mouse pointer. Gestures behave differently depending on which mode you are in and whether you are using Android or iOS.

• Scroll up or down: Swipe with two fingers.
• Click and drag:
  • Android: Drag with a finger.
  • iOS: Tap and hold, then drag with a finger.
• Zoom: Pinch and stretch with two fingers.
• Show keyboard (Android): Swipe up with three fingers.
• Show menu (iOS): Tap the screen with four fingers.
• Show the toolbar app: Swipe down with three fingers.
• Move the mouse (Trackpad): Swipe anywhere on the screen.
• Left click: Tap the screen.
• Right click (Trackpad): Tap the screen with two fingers.
• Middle click (Trackpad): Tap the screen with three fingers.

Access your computer when you’re not signed in to Google

Google gives you the option to share your computer with someone else. For security reasons, this is usually a bad idea because you’re giving them full access. But it can be useful if you want to connect to a remote computer from a device that is not signed in to your personal Google account, such as a work machine.

1. On the host machine, navigate to https://remotedesktop.google.com/support.
2. Click Generate Code. This generates a one time 12 access code.
3. On the guest machine, navigate to https://remotedesktop.google.com/support.
4. In the Access code field, enter the code you generated, and click Connect.

Using this connection method, you’ll be asked to confirm that you want to continue to share your computer every 30 minutes.

Troubleshooting

If you’re having problems, check that your network is configured to allow:

• Outbound UDP traffic.
• Inbound UDP responses.
• Traffic on TCP port 443 (HTTPS).
• Traffic on TCP and UDP on port 3478 (STUN).