htop Cheatsheet
Quick reference for monitoring processes, sorting tasks, filtering output, and managing processes with htop in Linux
The `htop` command is an interactive process viewer for Linux with color-coded meters, search, filtering, tree view, and keyboard shortcuts for managing processes. This cheatsheet covers the most useful startup options, navigation keys, sorting controls, process actions, and display settings.
Basic Usage
Start htop and limit the view when needed.
| Command | Description |
|---|---|
htop | Start htop with the default interactive view |
htop -u username | Show only processes owned by one user |
htop -p 1234,5678 | Monitor only the specified PIDs |
htop -t | Start in tree view |
sudo htop | Run with elevated privileges to manage more processes |
Navigation and Search
Move around the process list and find what you need quickly.
| Key | Description |
|---|---|
Arrow keys | Move up and down through processes |
Page Up / Page Down | Scroll one page at a time |
Home / End | Jump to the top or bottom of the list |
F3 or / | Search for a process by name |
F4 or \\ | Filter the process list |
Space | Tag or untag the selected process |
U | Clear all tags |
Sorting and Views
Change how processes are grouped and sorted.
| Key / Command | Description |
|---|---|
P | Sort by CPU usage |
M | Sort by memory usage |
T | Sort by running time |
F5 | Toggle tree view |
F6 | Choose a sort column |
htop -s PERCENT_MEM | Start sorted by memory usage |
H | Toggle display of user threads |
K | Toggle display of kernel threads |
Process Actions
Manage processes directly from inside htop.
| Key | Description |
|---|---|
F7 | Decrease nice value (raise priority) |
F8 | Increase nice value (lower priority) |
F9 | Send a signal to the selected process |
15 SIGTERM | Ask a process to exit cleanly |
9 SIGKILL | Force a process to stop immediately |
2 SIGINT | Interrupt a process, similar to Ctrl+C |
q or F10 | Quit htop |
Startup Options
Useful options for changing the initial view.
| Command | Description |
|---|---|
htop -d 20 | Refresh every 2 seconds |
htop -C | Use monochrome mode |
htop -H | Highlight new and old processes |
htop --readonly | Disable process-kill and renice actions |
htop --sort-key PERCENT_CPU | Start sorted by CPU usage |
Customization
Adjust the display and save the layout.
| Key / Path | Description |
|---|---|
F2 | Open the setup menu |
Columns | Add, remove, or reorder process columns |
Meters | Change header meters and display style |
Display options | Toggle tree lines, thread names, and other UI settings |
~/.config/htop/htoprc | Configuration file where settings are saved |
Troubleshooting
Quick checks for common htop issues.
| Issue | Check |
|---|---|
htop: command not found | Install htop with apt or dnf first |
| Cannot renice a process | Run htop with sudo to change priorities for other users’ processes |
| Cannot kill a process | Confirm you have permission, then use F9 with SIGTERM first |
| Process list is too noisy | Use F4 to filter or start with -u USER |
| Fast processes disappear | Lower the update interval with -d |
Related Guides
Use these guides for the full walkthroughs.
| Guide | Description |
|---|---|
htop Command in Linux | Full htop guide with examples |
top Command in Linux | Monitor processes in real time with top |
ps Command in Linux | List and inspect processes |
kill Command in Linux | Send signals to processes by PID |
pstree Command in Linux | View parent and child process relationships |