How to Check Your Kernel Version in Ubuntu Linux Using the uname Command

The “kernel” is the absolute core of the Linux operating system. It acts as the invisible bridge between the software you run (like your web browser) and the physical hardware inside your computer (like your processor and RAM). While Ubuntu handles kernel updates automatically in the background, there are times when you need to know exactly which version you are running. You might be troubleshooting a hardware compatibility issue, verifying that a critical security patch has been applied, or following a tutorial that requires a specific kernel release. Checking this information requires a simple terminal command.

Using the uname Command

The standard tool for querying core system information in Linux is uname (short for “Unix name”).

1. Open your terminal application (you can use the keyboard shortcut Ctrl + Alt + T).
2. To find out the specific version of the kernel you are currently running, you need to use the -r (release) flag.
3. Type the following command:
   uname -r
4. Press Enter.

Understanding the Output

The command will output a string of numbers and letters, for example: 6.8.0-31-generic.

This is not a random string; it is a highly structured versioning system. Here is how to read it:

• 6: This is the Mainline Version. It indicates a major, fundamental release of the Linux kernel architecture.
• 8: This is the Major Revision. It indicates significant new features, major driver additions, or substantial subsystem rewrites.
• 0: This is the Minor Revision. It usually indicates smaller bug fixes, security patches, and minor tweaks to the existing major revision.
• -31: This is the Patch/Build Number specific to the distribution. It shows how many times Canonical (the company behind Ubuntu) has specifically tweaked and recompiled this base kernel for their operating system.
• -generic: This indicates the Flavor of the kernel. “Generic” means it is a standard desktop/server kernel compiled to run on the widest possible variety of hardware. You might occasionally see “-lowlatency” or “-aws” (for cloud servers) here instead.

Getting More Detailed Information

If you need slightly more context, such as the exact date and time that specific kernel was compiled, you can use the -v (version) flag:

uname -v

Or, if you want a complete summary of your system architecture alongside the kernel release, use the -a (all) flag:

uname -a

This will output everything, confirming that you are running Linux, your hostname, your kernel release, the compile date, and your processor architecture (e.g., x86_64).