Does htop Support Mouse Wheel Scrolling?

The htop command-line utility for Linux does natively support mouse wheel scrolling, allowing users to navigate through the process list and menus using their mouse instead of relying solely on keyboard shortcuts. However, because htop runs inside a terminal emulator, the feature depends heavily on the terminal’s configuration and its ability to pass mouse events to the application. This article covers how to enable and use mouse scrolling in htop, troubleshoot common issues where scrolling fails, and configure your terminal emulator for the best experience.

How Mouse Interaction Works in htop

Unlike the traditional top command, htop uses the ncurses library to build a richer text-based user interface. When you launch htop, it attempts to capture mouse events from the terminal. If your terminal emulator supports it and has the feature active, you can:

• Scroll vertically through the process list using your mouse wheel.
• Click on specific processes to select them.
• Click on column headers (like CPU%, MEM%, or PID) to instantly sort the process list.
• Click the function keys (F1 through F10) listed at the bottom of the screen to trigger actions like filtering, searching, or killing a process.

Troubleshooting Mouse Scrolling Issues

If you open htop and find that spinning your mouse wheel does nothing, or if it scrolls your terminal buffer backward instead of scrolling the process list, the issue is usually caused by your terminal settings or your multiplexer.

Terminal Emulator Settings

Most modern terminals (such as GNOME Terminal, Alacritty, iTerm2, or Kitty) pass mouse events to ncurses applications by default. If yours does not, check your terminal’s preferences. Look for settings labeled “Report Mouse Tracking,” “Enable Mouse Input,” or “X11 Mouse Tracking” and ensure they are turned on.

Working with Terminal Multiplexers (tmux / Screen)

If you are running htop inside tmux or GNU Screen, mouse events are often intercepted by the multiplexer itself.

• In tmux: You must explicitly enable mouse support. You can do this temporarily by pressing Prefix (usually Ctrl+B), typing :set -g mouse on, and hitting Enter. To make this permanent, add set -g mouse on to your ~/.tmux.conf file.
• In Screen: Add mousetrack on to your ~/.screenrc file.

The Shift Key Bypass

If you want to highlight and copy text from htop using your mouse rather than scrolling or clicking UI elements, most Linux terminals allow you to bypass htop’s mouse capture by holding down the Shift key while clicking or dragging.