Helm vs Kustomize: Which One Should You Choose?

When deploying applications in Kubernetes, two of the most popular tools for managing configuration are Helm and Kustomize. Both aim to make deploying manifests more manageable, but they follow different philosophies and offer distinct features.

Table of Contents

  1. What is Helm?
  2. What is Kustomize?
  3. Key Differences
  4. Pros and Cons
  5. Use Cases and Recommendations
  6. Example Configurations
  7. Conclusion

1. What is Helm?

Helm is a package manager for Kubernetes. It lets you define, install, and upgrade even the most complex Kubernetes applications using Helm charts.

Key Features:

  • Chart-based templates
  • Dependency management
  • Versioning and rollback
  • Built-in templating with Go templates
helm repo add bitnami https://charts.bitnami.com/bitnami
helm install myapp bitnami/nginx

2. What is Kustomize?

Kustomize is a tool built into kubectl that lets you customize raw, template-free YAML files for multiple environments.

Key Features:

  • Native in kubectl
  • Overlay system for dev/stage/prod
  • Pure YAML, no templating
  • Composition through patches and bases
kubectl apply -k ./overlays/production/

3. Key Differences

FeatureHelmKustomize
Template SupportYes (Go templates)No
Native to kubectlNoYes
Package ManagerYesNo
Complexity HandlingGood for complex appsGreat for structured overlays

4. Pros and Cons

Helm

✅ Reusability with charts
✅ Strong community support
❌ Complexity in large templates
❌ Debugging template issues can be hard

Kustomize

✅ Simple overlays for environments
✅ Works with existing YAML
❌ No templating (you repeat things)
❌ Less community adoption

5. Use Cases and Recommendations

  • Use Helm if you want a full-featured package manager and need templating logic.
  • Use Kustomize if you prefer working with raw YAML and want straightforward environment-specific overlays.

6. Example Configurations

Helm Example Chart

helm create mychart
helm install myapp ./mychart

Kustomize Overlay Example

# kustomization.yaml
resources:
  - ../../base
patchesStrategicMerge:
  - deployment-patch.yaml

7. Conclusion

Both tools are excellent — the choice depends on your workflow and team preferences. Helm is powerful for packaging and reusability, while Kustomize shines for YAML purity and simplicity.

If you’re new to Helm or want a detailed guide on how to use it, check out my Helm Basics: What is Helm and How to Use It?