Install the app

Get the desktop app onto each computer you want to control or be controlled.

Install the same app on both computers. Download it from humbleviewer.com.

Windows

1. Run humble-windows-x86_64-<version>.msi. It installs to C:\Program Files\Humble and adds a Start menu entry. On the Unattended access page, leave Allow unattended access off unless this computer must be reachable when nobody is at it (see Unattended access). You can change it later in Windows Settings, Apps, Humble Viewer, Modify.
2. Open Humble Viewer from the Start menu.

Other ways to install:

• Portable: run humble.exe without installing. It works while the window is open.
• Silent: msiexec /i humble-windows-x86_64-<version>.msi /qn installs the app only; add UNATTENDED=1 for the background service.
• Silent, joining your server: msiexec /i humble-windows-x86_64-<version>.msi /qn ENROLL=<code> (with the background service; add UNATTENDED=0 to leave it out). The code comes from the dashboard's Deploy page. See Deploy.

Upgrading: run the newer installer. It closes Humble (the tray icon, open windows and the background service), replaces it, and starts the service and the tray icon again, keeping your choice of the background service. No restart is needed. Removing or repairing Humble closes it the same way.

macOS

1. Open humble-macos-universal-<version>.dmg and drag Humble to Applications.
2. Open it. If macOS says the app is from an unidentified developer, right-click the app and choose Open.
3. To let others control this Mac, open System Settings → Privacy & Security and turn Humble on under both Screen Recording and Accessibility. Then quit and reopen Humble.

You only need those two permissions on a Mac that will be controlled. A Mac that only controls other computers needs neither.

Ubuntu and Debian

Each release has its own package, built against its version of FFmpeg (for encoding video on the graphics card). Pick the one whose name ends in your release: debian12, ubuntu24.04 or ubuntu26.04, and amd64 for Intel and AMD or arm64 for ARM. For example, on Ubuntu 24.04:

sudo apt install ./humble_<version>-1~ubuntu24.04_amd64.deb

Then log out and back in once, and start Humble Viewer from the applications menu or run humble.

On another distribution, use the plain humble-linux-x86_64 or humble-linux-aarch64 program. It needs glibc 2.36 or newer (Debian 12, Ubuntu 24.04 and later) and encodes video in software, without the graphics card.

Fedora

The package is built for Fedora 44 on Intel and AMD computers:

sudo dnf install ./humble-<version>-1.fc44.x86_64.rpm

Then log out and back in once. Fedora's own FFmpeg leaves out some encoders; where it has no H.264 encoder for your graphics card, Humble encodes video in software.

Fedora's GNOME shows no tray icons until you add the AppIndicator extension; without it Humble works the same, just without the tray icon:

sudo dnf install gnome-shell-extension-appindicator
gnome-extensions enable appindicatorsupport@rgcjonas.gmail.com

Log out and back in for it to take effect.

Arch Linux and Omarchy

sudo pacman -U humble-<version>-1-x86_64.pkg.tar.zst

Or build the package yourself from the repository:

cd packaging/arch
makepkg -si

Log out and back in once afterwards. Omarchy is Arch with Hyprland, so it uses the same package.

Linux: Wayland notes

This applies to GNOME on Wayland, KDE on Wayland, and Hyprland (Omarchy).

• Screen sharing on Hyprland (Omarchy), sway and similar: works without any prompt.
• Screen sharing on GNOME and KDE: goes through the desktop's own screen-sharing dialog. When someone connects, the computer being controlled shows a prompt asking which screen to share, and someone has to accept it.
• Humble must be started from inside the desktop session (the applications menu, a terminal in that session, or the background service). XWayland must be enabled, which it is by default on all of these desktops.
• Remote input uses a virtual keyboard and mouse. The package installs a rule that gives the logged-in user access to it, which is why you need to log out and in once after installing.

On X11 none of this applies; capture and input work without prompts.

Firewall: allow direct connections

To be reached directly by another computer, a computer must accept incoming connections on TCP port 21420. Many systems block this by default. You do not need any of this when both computers use a Humble server, because they only make outgoing connections.

sudo ufw allow 21420/tcp
sudo ufw allow 5353/udp     # optional: appear under Nearby

sudo firewall-cmd --permanent --add-port=21420/tcp
sudo firewall-cmd --reload

netsh advfirewall firewall add rule name="Humble Viewer" dir=in action=allow protocol=TCP localport=21420 profile=private,domain

Signs that a firewall is the cause: the connection attempt waits about ten seconds and then reports no answer, while ping to the same address works.

First run

The main window has two cards:

• This device shows what someone else needs to reach this computer: your address (or your ID, once you use a server) and a one-time password.
• Connect to a computer is where you type the other computer's address or ID.

Continue with Connect and control.

Uninstall