Zsh is the shell; Oh My Zsh is the framework that manages your Zsh configuration. This guide shows a minimal and reliable setup on Ubuntu or Debian, then adds a small optional section for common plugins.

Why use Oh My Zsh instead of plain Bash?

For shell scripting, Bash is still the safer default because it is installed almost everywhere and many CI systems assume it. For interactive terminal work, however, Zsh plus Oh My Zsh is usually more efficient.

The main benefit is not raw execution speed. Commands do not run faster just because you use Oh My Zsh. The real gain is interactive efficiency: fewer keystrokes, fewer command mistakes, and less context switching.

Common advantages for developers:

• Better completion. Zsh generally provides stronger tab completion than plain Bash, and Oh My Zsh gives a ready-to-use configuration on top of it.
• Better prompt context. Most themes show useful information such as the current Git branch, so you do not need to run git status as often.
• Plugin-based workflow. Built-in plugins add aliases and helpers for tools such as git, docker, kubectl, python, and vscode.
• Faster repeated commands. With autosuggestions, previous commands can be accepted with a keystroke instead of retyping them.
• Fewer typing mistakes. Syntax highlighting helps you catch invalid commands, bad paths, or incomplete options before pressing Enter.
• Easier customization. Instead of building a shell setup from scratch, you start from a sensible ~/.zshrc and extend it gradually.

In practice, this means less time spent remembering long commands, checking repository state, or fixing small terminal mistakes.

Prerequisites

• Ubuntu or Debian-based Linux
• sudo access
• curl
• git

1. Install Zsh

Install Zsh and the tools used by the Oh My Zsh installer:

sudo apt update
sudo apt install -y zsh curl git

Verify the shell is available:

zsh --version

If you already have a custom ~/.zshrc, back it up before running the installer:

cp ~/.zshrc ~/.zshrc.bak

2. Install Oh My Zsh

Run the official installer:

sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

The installer creates ~/.oh-my-zsh and a starter ~/.zshrc. In many cases it also switches you into Zsh immediately.

3. Make Zsh the default shell

Set Zsh as your login shell:

chsh -s "$(command -v zsh)"

Start a new terminal session, or switch immediately in the current shell:

exec zsh

4. Edit ~/.zshrc

The two most common changes are the theme and the built-in plugin list:

ZSH_THEME="robbyrussell"
plugins=(git)

git is bundled with Oh My Zsh, so no extra installation is needed. Reload the config after each edit:

source ~/.zshrc

5. Optional: Common plugins

Oh My Zsh ships with many built-in plugins, but popular plugins such as autosuggestions and syntax highlighting are external and must be installed separately.

Built-in plugins

These work by editing the plugins=(...) line in ~/.zshrc:

plugins=(git sudo vscode)

• git adds many Git aliases
• sudo lets you press Esc twice to prepend sudo to the previous command
• vscode adds helpers for opening files and folders in VS Code

External plugins

Install zsh-autosuggestions and zsh-syntax-highlighting into the Oh My Zsh custom plugin directory:

git clone https://github.com/zsh-users/zsh-autosuggestions \
  ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions

git clone https://github.com/zsh-users/zsh-syntax-highlighting.git \
  ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting

Then enable them in ~/.zshrc:

plugins=(git sudo vscode zsh-autosuggestions zsh-syntax-highlighting)

Keep zsh-syntax-highlighting at the end of the list. Reload the shell:

source ~/.zshrc

Troubleshooting

chsh fails

Make sure the Zsh path is allowed by the system:

which zsh
cat /etc/shells

If needed, add it once and retry:

echo "$(command -v zsh)" | sudo tee -a /etc/shells
chsh -s "$(command -v zsh)"

Plugins do not load

Check the following:

1. The plugin name in plugins=(...) matches the directory name under ~/.oh-my-zsh/custom/plugins/.
2. External plugins were cloned successfully.
3. zsh-syntax-highlighting is last in the plugin list.
4. You reloaded the shell with source ~/.zshrc or opened a new terminal.

Quick Reference

sudo apt install -y zsh curl git
sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
chsh -s "$(command -v zsh)"
exec zsh
source ~/.zshrc