How to show the kernel version in Linux

Kernel release numbers matter whenever driver support, module compatibility, security tracking, or vendor instructions depend on the exact kernel that is running on the host. Showing the active release quickly confirms whether a reboot actually switched kernels and whether a package, module, or troubleshooting step applies to the current system.

In Linux, uname -r is the quickest way to print the running kernel release, which is the value most package, support, and compatibility checks expect. Add other uname flags only when the same check also needs the machine architecture or the kernel build string.

The related /proc/version file exposes the running kernel type, release, and build string as one longer line. Containers share the host kernel, so uname inside a container reports the host kernel rather than a separate container-specific kernel, and build strings vary widely between distributions and vendors.

1. Print the running kernel release with uname -r.

   $ uname -r
   6.12.76-linuxkit

   Use -r for most checks because plain uname prints only the kernel name, usually Linux. The release string identifies the kernel that is currently booted, not every kernel package installed on disk.

2. Print the release and machine architecture together when packages, modules, or downloads differ by platform.

   $ uname -rm
   6.12.76-linuxkit aarch64

   -m adds the hardware name such as x86_64 or aarch64, which helps distinguish kernels with the same release string on different architectures.

3. Print the kernel build string when a ticket, audit note, or vendor request needs the exact build metadata.

   $ uname -v
   #1 SMP Sun Mar  8 14:41:59 UTC 2026

   -v prints the kernel version string, which usually includes the build number, SMP or PREEMPT markers, and the vendor build timestamp.

4. Read the full kernel identity line from /proc/version when release and build details need to stay on one line.

   $ cat /proc/version
   Linux version 6.12.76-linuxkit (root@buildkitsandbox) (gcc (Alpine 15.2.0) 15.2.0, GNU ld (GNU Binutils) 2.45.1) #1 SMP Sun Mar  8 14:41:59 UTC 2026

   /proc/version combines the running kernel type, release, and version fields into one line. The release near the start of the line is the most portable part to compare across different distributions and vendors.