What are the differences between K3S vs K8S? An overview

The main difference between K3S and the standard Kubernetes installation (K8S) is complexity and resource consumption. K3S is a lightweight, streamlined version of Kubernetes built for resource-constrained environments and edge computing, while K8S is the full-featured, standard Kubernetes platform.

What are K3S and K8S?

K3S is a lightweight Kubernetes distribution created by Rancher Labs. It is fully compatible with K8S APIs, but removes non-essential components and tools to greatly reduce resource usage. This streamlined design makes K3S an excellent choice for edge computing, IoT devices, and small servers where traditional Kubernetes clusters would be too resource-heavy.

K8S is the leading open-source platform for container orchestration and is often regarded as the ‘classic’ form of Kubernetes. It enables the management, scaling, and automation of containerised applications in large production environments. K8S includes powerful features such as self-healing, rolling updates, and load balancing. This flexibility makes it well-suited for enterprise clusters, cloud infrastructures, and complex microservice architectures. However, K8S also requires significantly more resources and administrative expertise.

The differences between K8S and K3S

The differences in the comparison of K3S vs K8S can be summarised in several key points.

1. Resource consumption

K3S was intentionally designed for environments with limited resources. It leaves out many extra components, such as standard Kubernetes controllers, ingress controllers, and extensive logging. As a result, a K3S cluster consumes far less RAM and CPU power than a K8S cluster while still providing the core functions of container orchestration. In contrast, K8S is built to scale for large clusters and offers the full feature set, which comes with significantly higher resource demands.

2. Installation and setup

Installing K3S is highly simplified: a single command is enough to deploy either a master node or a multi-node cluster. By default, it also includes the container runtime and network plugins. K8S, on the other hand, requires multiple steps—such as installing Kubelet, Kube-Proxy, the API server, and other components—along with network configuration. As a result, K8S is considerably more complex and time-consuming to set up.

3. Feature scope and components

K3S intentionally narrows its scope to the core features needed in most scenarios, with additional extensions requiring manual setup. K8S, by contrast, delivers a full feature set out of the box, including comprehensive APIs, monitoring, logging, and cloud platform integrations. It also relies on several external dependencies, such as etcd for cluster state storage and separate components like kube-apiserver, kube-controller-manager, and kube-scheduler. K3S minimises non-essential components, bundles everything into a single binary, and defaults to SQLite instead of etcd.

4. Target environment

K3S is especially well-suited for edge computing, IoT, testing and development environments, or small production systems. K8S, by contrast, is designed for large, scalable clusters in data centres and cloud infrastructures. The right choice largely depends on the intended workload and the resources available.

5. Security

K8S is built for multi-tenant environments and enterprise security, offering advanced features such as role-based access control, flexible secret management, and encryption. K3S also supports role-based access control and policies, but omits certain security features by default to save resources. However, these can be added later with Kubernetes-native tools, making K3S a practical choice for edge deployments and single-tenant environments.

6. Compatibility and community

K3S is fully compatible with K8S, but not every K8S extension is included by default. Its community is smaller, yet highly focused on lightweight setups and rapid deployment. K8S, on the other hand, has the largest community in container orchestration, with extensive documentation and broad support for extensions.

When to choose K3S or K8S? A comparison

K3S is particularly valuable when infrastructure is limited or when fast and easy deployments are required. Common scenarios include edge computing devices, small servers, IoT applications, and development or testing environments. It is also an efficient option for individual microservice applications or projects with limited scope and scalability needs, since it conserves both storage and CPU resources.

K8S, by contrast, is designed for large-scale production environments where high availability, load balancing, self-healing, and scalability are essential. Organisations use K8S to orchestrate complex microservice architectures, run cloud-native applications, and manage clusters across multiple data centres. The platform is especially well-suited for teams that need advanced monitoring and logging capabilities, integrated security policies, or comprehensive storage integrations.

For hybrid use cases, it can be advantageous to deploy K3S at the edge or for development environments, while running K8S in the cloud for central production clusters. In summary, K3S is lighter, faster, and more resource-efficient, whereas K8S is more comprehensive, scalable, and enterprise-ready.

Alternatives to K3S and K8S

In addition to K3S and K8S, there are several other Kubernetes distributions and container orchestration platforms that may be useful depending on the scenario:

• MicroK8s: MicroK8s is a lightweight Kubernetes distribution developed by Canonical. It is well-suited for developers, small clusters, or testing environments. Modular and quick to install, it can be extended with add-ons such as DNS or monitoring as needed. Its simplicity makes it easy for developers to experiment with K8S locally before moving to larger clusters.
• Minikube: Minikube is designed specifically for local development environments. It provides a fast and simple way to run Kubernetes on a single machine and test containerised applications. While not intended for production clusters, Minikube is an excellent tool for learning Kubernetes features or building prototypes.
• OpenShift: OpenShift is a Kubernetes-based platform from Red Hat that includes additional security and enterprise features. It is particularly appealing for large companies that need standardised Kubernetes clusters with enhanced management and security functions. OpenShift can be deployed on-premises or in the cloud.
• Docker Swarm: Docker Swarm is a simpler container orchestration solution built into Docker. Less complex than Kubernetes, it provides essential orchestration functions and is suitable for smaller projects where advanced infrastructure is unnecessary but container orchestration is still required.