Linux - top & htop in Linux

 What is top?

top is a default, command-line system monitor in Linux that displays real-time information about:

  • CPU usage

  • Memory usage

  • Running processes

  • Load average

  • Swap usage

  • Process IDs, states, priorities

How it looks

It opens inside the terminal and updates every 3 seconds by default.

Key Use Cases

  • Identify processes consuming high CPU/RAM

  • Monitor load average

  • Kill or renice processes

Useful Keys in top:

Key Action
P Sort by CPU usage
M Sort by Memory usage
k Kill a process
r Renice (change priority)
q Quit

2️⃣ What is htop?

htop is a modern, interactive, user-friendly system monitor — an improved version of top.

It has:

  • Colorful display

  • Graphs for CPU, memory, swap

  • Scrollable list of processes

  • Mouse support

  • Easier process killing and sorting

Why users prefer htop:

✔ Better UI
✔ Easier navigation
✔ Search option
✔ Shows full command paths
✔ Color-coded resource usage

Install htop

 
sudo apt install htop # Debian/Ubuntu sudo yum install htop # CentOS/RHEL sudo dnf install htop # Fedora

3️⃣ Key Differences (top vs htop)

Feature top htop
Interface Basic, text-only Colorful, interactive
Navigation Keyboard only Keyboard + mouse
Process list Not scrollable Scrollable
Sorting Manual keys (P, M) One-click / function keys
CPU/Mem Graphs No Yes
Kill process Press k Press F9 (menu)
Full command line Not always visible Always visible
Install Comes pre-installed Needs installation

Summary: