How to Check Your Linux System Architecture (32-bit vs 64-bit)

When you are downloading third-party software, installing a new application from source, or configuring a Docker container, you will frequently be asked to choose between a 32-bit (x86) or 64-bit (x86_64) version of the software.

If you download the wrong architecture, the software simply will not run. Therefore, knowing the underlying architecture of your Linux operating system and your CPU is essential. You can find this out instantly using a few simple terminal commands.

Method 1: Using the uname Command

The uname (Unix name) command is the fastest and most standard way to check your system architecture. It works on virtually every Linux distribution in existence, from Ubuntu to CentOS to Arch.

1. Open your Linux terminal.
2. Type the following command and press Enter:
   uname -m

Understanding the Output:

• If the terminal outputs x86_64, your system is running a 64-bit architecture. (You might also see aarch64 if you are running a 64-bit ARM processor like a Raspberry Pi 4).
• If the terminal outputs i686, i386, or x86, your system is running a 32-bit architecture.

Method 2: Using the arch Command

The arch command is essentially just a shortcut for uname -m. It performs the exact same function but is slightly faster to type.

1. Open your terminal.
2. Type the following command and press Enter:
   arch

The output will be identical to the previous method (e.g., x86_64).

Method 3: Detailed Info Using lscpu

If you want to know not only what architecture your operating system is currently running, but what architectures your physical CPU is capable of running, you should use the lscpu command.

1. Open your terminal.
2. Type the following command and press Enter:
   lscpu

This command will dump a large block of detailed hardware information onto your screen. Look at the very top for two specific lines:

• Architecture: This confirms what the OS is running (e.g., x86_64).
• CPU op-mode(s): This is the most important line. If it says 32-bit, 64-bit, it means your physical processor supports both, and you could install a 64-bit OS if you aren’t already using one. If it only says 32-bit, your physical hardware is very old and physically cannot run modern 64-bit software.