YAML Formatter Online — Free Beautifier & Pretty Printer

Beautify YAML with consistent 2 or 4-space indentation. Clean up Kubernetes manifests, Docker Compose, GitHub Actions, and Helm chart values for clean diffs and clean commits.

Input YAML

Formatted YAML

What is a YAML Formatter?

A YAML formatter rewrites a YAML document with canonical, consistent indentation and spacing. Same data, same structure, same keys — just normalised whitespace. The result is easier to read, far easier to diff in code review, and produces noise-free Git history when teammates use different editors.

OpenFormatter's YAML formatter (also called a YAML beautifier or YAML pretty printer) accepts any well-formed YAML — Kubernetes manifests, Docker Compose, GitHub Actions, Ansible playbooks, Helm values, OpenAPI specs — and emits a clean version with your chosen indent size. It runs entirely in the browser, so even YAML containing secrets and credentials stays on your device.

How to format YAML online — 4 steps

Paste your YAML. Drop a manifest or config into the Input panel — or click Load Sample for a messy YAML to clean up.
Pick indent size. Toggle 2 sp (Kubernetes/Docker default) or 4 sp (occasional Ansible style).
Click Format. The formatter parses the document and rewrites it with canonical whitespace.
Copy or commit. Copy the cleaned version back into your editor, or paste into a Git commit for a noise-free diff.

Before and after — formatting messy YAML

Before

apiVersion:    v1
kind:    Service
metadata:
   name:   web
   labels:
        app:   web
spec:
    type:  ClusterIP
    ports:
       - port:    80

After (2-space)

apiVersion: v1
kind: Service
metadata:
  name: web
  labels:
    app: web
spec:
  type: ClusterIP
  ports:
    - port: 80

Consistent Indentation

Normalises mixed indentation, irregular spacing, and tabs into clean 2 or 4-space indent throughout the entire document.

Standards Compliant

Output follows the YAML 1.2 conventions used by Kubernetes, Docker Compose, Helm, GitHub Actions, and Ansible.

No Server Processing

Formatting runs in JavaScript locally. YAML containing secrets, kubeconfig, or credentials never touches a server.

When to format YAML

check_circleBefore committing a Kubernetes manifest to Git so PR diffs show only data changes
check_circleAfter hand-editing a Compose file in a quick text editor that did not auto-indent
check_circleCleaning up YAML pasted from chat tools that mangle whitespace
check_circleNormalising YAML emitted by tools like Helm template, Kustomize, or kubectl get -o yaml
check_circleReformatting Ansible playbooks for consistent style across a team
check_circleCleaning up GitHub Actions workflows authored by multiple contributors
check_circlePreparing YAML to embed in documentation or onboarding docs
check_circleFixing YAML in a CI pipeline with a pre-commit hook

2-space vs 4-space — which should you use?

Both are valid YAML. The convention depends on the ecosystem your file targets:

2 spaces — Kubernetes, Docker Compose, Helm charts, GitHub Actions, GitLab CI, CircleCI, OpenAPI/Swagger. This is the dominant default in cloud-native tooling.
4 spaces — Some Ansible playbooks (especially older codebases). Rare elsewhere.

If you are unsure, choose 2 spaces — every public manifest you read on GitHub and every Helm chart on Artifact Hub uses it. Pick one and apply it across the whole repository: mixing the two creates ugly diffs.

Validate or convert your YAML next

Pair the formatter with the rest of OpenFormatter's YAML toolkit — all browser-based.

YAML Validator YAML Viewer YAML to JSON

Frequently Asked Questions

What does a YAML formatter do?

A YAML formatter parses a YAML document and rewrites it with canonical, consistent indentation and spacing. It does not change the data — only the whitespace. The result is a clean, normalised file that is easy to review, easy to diff in pull requests, and trivially compatible with kubectl, docker compose, helm, and ansible.

Should I use 2-space or 4-space indentation in YAML?

Two-space indentation is the de-facto standard in the Kubernetes, Docker, GitHub Actions, and Helm communities. Most public manifests, Compose files, and chart values use two spaces. Four-space is occasionally seen in larger Ansible playbooks. Pick one and apply it across the repository — mixing the two creates confusing diffs.

Will the formatter remove my comments?

Most online YAML formatters strip comments because YAML libraries discard them during parsing. If preserving comments is essential — for example, a Helm values file with documentation comments — keep a copy of the original or use a comment-preserving formatter like prettier with the YAML plugin or yq with --inplace.

Does formatting change the data in my YAML?

No. Formatting only adjusts whitespace — indentation, blank lines, and spacing around colons. Keys, values, list items, and the tree structure stay identical. If your formatted file behaves differently, the original was likely ambiguous (mixed tabs/spaces or duplicate keys) and the formatter resolved the ambiguity.

Can I format multi-document YAML files (with --- separators)?

Yes. Each document between --- separators is parsed and formatted independently. The formatter preserves the document boundaries, so a multi-Resource Kubernetes manifest comes out as separate cleanly-formatted documents in the same file.

Is the YAML formatter the same as a YAML beautifier or pretty printer?

Yes. "YAML formatter", "YAML beautifier", and "YAML pretty printer" all describe the same operation: producing a canonical, indented, human-readable YAML output from any valid input. The terms are used interchangeably.

Why is my YAML rejected when I click Format?

Formatting requires the input to be valid YAML. If the document has tabs in indentation, duplicate keys at the same level, missing colons, or unbalanced quotes, the parser fails and the formatter cannot produce output. Use the YAML Validator first to find and fix the error, then format.

Is my YAML data uploaded?

No. Formatting runs in JavaScript inside your browser. YAML files containing secrets, tokens, kube credentials, or proprietary configuration never leave the device. Verify by opening DevTools → Network — no requests are made when you click Format.