How to Kill a Process in Linux Easily

When a Linux process goes rogue or eats up too much CPU/RAM, you’ve got to terminate it manually - that’s where kill commands come in handy! In this guide, you’ll learn all the ways to kill processes in Linux using the terminal like a real sysadmin.

What You Need to Know Before Killing a Process​

In Linux, only root (or a user with sudo privileges) can terminate any process.
If you’re not root, just type sudo before the command.

There are a few signal types to end a process:

• SIGTERM - A polite “please close” request
• SIGKILL - A forceful “close now!” command

Tip: Always try SIGTERM before SIGKILL. The latter doesn’t let programs save their data!

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Step 1: View All Running Processes​

Use the top command to see everything currently active: top

• Press k to kill a process directly from the list.
• Press q to quit.

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Step 2: Find the Process You Want to Kill​

Using ps Command​

Shows running processes with detailed info: ps -aux

The options mean:

• -a: all users
• -u: detailed info
• -x: system/daemon processes

Using pgrep or pidof​

If you know part or all of a process name:

pgrep -u root apache
pidof firefox

These commands return the PID (Process ID), which you’ll use to kill it.

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Step 3: Kill the Process​

Using killall​

Kill processes by name:

sudo killall firefox

Optional flags:

• -i: ask for confirmation
• -v: show results
• -o 10m: kill processes older than 10 minutes

Using pkill​

Similar to pgrep, but it actually kills the process:

sudo pkill -u root apache

Using kill by PID​

When you have the process ID:

sudo kill 1234

To force kill:

sudo kill -9 1234

or

sudo kill -SIGKILL 1234

Warning: kill -9 skips cleanup routines - data loss possible!

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Step 4: Use GUI or xkill (For Desktop Users)​

If you’re using a graphical environment, type: xkill
Then click on the unresponsive window - problem solved!

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Quick Recap​

• Use top, ps, or pgrep to find the process.
• Use kill, killall, or pkill to terminate it.
• Use sudo for permission issues.
• Use kill -9 only when nothing else works.

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Bonus Tip​

Want to keep a command running even after logout?
Learn about the nohup command - it blocks signals like SIGHUP so your processes don’t die when the terminal closes.