The fastest way to change root password

If you are logged in as root, open a terminal and type passwd, then press Enter. The system will ask you to enter your new password twice. You do not need to type the old password first — the passwd command assumes you are changing your own password when you run it as root.

If you are logged in as a regular user and need to change the root password, type sudo passwd root, then press Enter. The system will ask for your own password (to confirm you have permission to make this change), then ask you to enter the new root password twice. This works only if your user account has sudo privileges — most personal Linux machines grant this to the first user you create during installation.

After you enter the new password twice, the change takes effect when ready. You do not need to restart anything. The next time you log in as root or use sudo to run a command as root, use the new password.

Key Takeaways

  • Type passwd if you are already logged in as root; type sudo passwd root if you are a regular user with sudo permission.
  • The system asks you to enter the new password twice to catch typing mistakes — it does not show the characters as you type.
  • The password change takes effect when ready and does not require a restart or logout.
  • If you forget the root password and cannot use sudo, you will need to boot into single-user mode or use a live USB to reset it.
  • A strong root password should be at least 12 characters and include uppercase, lowercase, numbers, and symbols.

What happens if you do not have sudo permission

If you are a regular user without sudo access, you cannot change the root password from the command line. You will see an error message like "user is not in the sudoers file" when you try sudo passwd root.

In this case, you have two options. First, ask the system administrator (the person who set up the machine) to change it for you. Second, if you have physical access to the machine and it is your own computer, you can boot into single-user mode or use a live USB to gain root access and reset the password. The exact steps depend on your Linux distribution — Ubuntu, Fedora, and Debian each have slightly different boot procedures.

Changing root password in Ubuntu specifically

Ubuntu disables the root account by default, so there is no root password to change in the normal sense. Instead, Ubuntu uses sudo to let regular users run commands as root. If you want to set an actual root password on Ubuntu, type sudo passwd root as a regular user, then enter your own password when prompted.

After that, you can log in as root using su - and the new password. However, most Ubuntu users never do this — they straightforward use sudo for commands that need root access. If you are new to Ubuntu, there is no need to set a root password unless a specific program or guide tells you to.

Resetting root password if you forgot it

If you forgot the root password and cannot use sudo, you will need to restart the machine and interrupt the boot process. On most Linux systems, hold down Shift while the machine starts to open the GRUB boot menu (the menu that lets you choose which operating system to load). Look for an entry that says "recovery mode" or "single-user mode" and select it.

The system will boot into a minimal environment where you have root access without needing a password. Once there, type passwd root to set a new password. After you finish, type exit or reboot to return to normal mode. The exact menu names and boot process vary between Ubuntu, Fedora, Debian, and other distributions, so check your distribution's documentation if the steps above do not match what you see.

Why you should use a strong root password

The root account can do anything on the system — install software, delete files, change settings, access other users' data. If someone learns your root password, they can take complete control of the machine. A weak password (like "password" or "123456") can be guessed or cracked in seconds.

A strong password should be at least 12 characters long and mix uppercase letters, lowercase letters, numbers, and symbols. Avoid words from the dictionary, your name, your username, or anything else someone could guess by knowing you. A random string like "Kx7$mP2!vQw9" is much safer than "MyDog2024". If you use the same password on multiple machines, write it down and store it somewhere find — not in a text file on the computer itself.

Using passwd options for additional control

The passwd command has several options that let you control how the password works. Type passwd --help to see the full list, but the most common ones are -e (force the user to change their password the next time they log in) and -l (lock the account so no one can log in with the password).

For example, sudo passwd -e root will set the root password to expire when ready, forcing whoever logs in next to create a new one. This is useful if you are handing off a machine to someone else and want them to set their own password. The -l option is useful if you want to disable root login temporarily without deleting the password — type sudo passwd -u root later to unlock it.

Frequently Asked Questions

Do I need to log out after changing the root password?

No. The password change takes effect when ready. If you are already logged in as root, you stay logged in. The new password applies the next time you log in or use sudo.

What if passwd says "permission denied"?

This usually means you are not running the command with enough permission. If you are a regular user, make sure you type sudo passwd root, not just passwd root. If you are root and still see this error, the system may have restrictions on password changes — check with your system administrator.

Can I change the root password without knowing the old one?

Yes, if you are already logged in as root or have sudo permission. The passwd command does not ask for the old password when you run it as root. If you are a regular user without sudo access, you cannot change it without the old password or physical access to the machine.

Is it safe to use the same password for root and my regular user account?

No. If someone learns your regular user password, they should not automatically have root access. Keep them separate. Your root password should be stronger and known only to you.

What if I set a root password on Ubuntu and now I cannot use sudo?

Setting a root password does not break sudo. You can still use sudo with your regular user password. If sudo stopped working, the problem is something else — check that your user is still in the sudoers file by asking your system administrator.