kubeconform

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Introduction

kubeconform validates Kubernetes manifests against the official JSON schemas for a chosen Kubernetes version. The README describes it as a fast manifests validator with support for custom resources.

It is a successor in spirit to kubeval: it validates files or directories concurrently, can use schema registries for CRDs, caches schemas, and reports in text, JSON, JUnit or TAP. Pointing it at the Kubernetes version you deploy to catches removed or misspelled fields before kubectl apply does.

In the quality loop, kubeconform is a cheap pre-merge check, often run on rendered Helm or Kustomize output.

The source code is at yannh/kubeconform on GitHub under the Apache-2.0 licence, with about 3,300 stars; the most recent commit was on 13 June 2026.

Features

1. Schema validation: Checks manifests against Kubernetes JSON schemas.
2. CRD support: Custom schema locations for custom resources.
3. Version targeting: Validate against a specific Kubernetes version.
4. Concurrency: Validates many files quickly.
5. Output formats: Text, JSON, JUnit and TAP.
6. Strict mode: Reject unknown fields.

Pros

1. Very fast: Suitable for every pull request.
2. Free to use: Open source under the Apache-2.0 licence, so the core tool costs nothing to use.
3. Actively maintained: The repository had commits as recent as 13 June 2026.
4. Community: About 3,300 GitHub stars.

Cons

1. Schema only: Does not check best practices or security.
2. CRD schemas: You must supply schemas for custom resources.
3. Slower release cadence: Releases are infrequent.

Usage and Links (Example)

helm template ./chart | kubeconform -strict -summary -kubernetes-version 1.34.0 \
  -schema-location default \
  -schema-location 'https://raw.githubusercontent.com/datreeio/CRDs-catalog/main/{{.Group}}/{{.ResourceKind}}_{{.ResourceAPIVersion}}.json'

Resources:

• kubeconform website

Pricing

kubeconform is free and open source under the Apache-2.0 licence.

Recommended for?

1. GitOps repositories validating rendered manifests.
2. Chart authors checking output against target Kubernetes versions.

Conclusion

kubeconform is a quick, reliable schema check for Kubernetes YAML.

Pair it with kube-score or kube-linter for best-practice checks.

On CheckOps, kubeconform is filed under the Release & CI gates stage. Related tools listed here include KUTTL, Chainsaw, kind, helm-unittest, chart-testing and kube-score. Before standardising on one, compare recent maintenance activity, the pricing model as your usage grows, and the integrations you rely on today. Information on this page was verified against the official website, documentation and repository on 11 November 2026.