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YAML Beautifier

Paste messy or inconsistently indented YAML and get it formatted cleanly in one click. Validate syntax, sort keys, and download the result.

Last updated: May 20, 2026

Client-Side Processing
Input Data Stays on Device
Instant Local Execution

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What is YAML Beautifier?

YAML (YAML Ain't Markup Language) is the standard format for configuration files in modern software — Kubernetes manifests, GitHub Actions workflows, Docker Compose files, Ansible playbooks, and countless application configs all use YAML. Poorly indented or manually edited YAML is one of the most common sources of confusing errors, because YAML is whitespace-sensitive: incorrect indentation silently changes the data structure.

A YAML beautifier re-parses your input and re-serializes it with consistent indentation so the structure is clear and the file is guaranteed to produce the same data as before. The validator catches syntax errors before they reach a CI pipeline or deployment.

How to Use YAML Beautifier

1

Paste your YAML into the input area or click "Load Sample"

2

Set the indent size (2 or 4 spaces)

3

Optionally enable "Sort Keys" to alphabetise all object keys

4

Click "Format" — the validation badge updates as you type

5

Copy the output or download it as a .yaml file

Common Use Cases

  • DevOps engineers normalising Kubernetes manifests and Helm chart values files before code review.
  • Developers cleaning up GitHub Actions workflow YAML after editing multiple steps.
  • Teams enforcing consistent formatting in Docker Compose files across contributors.
  • Ansible users formatting playbook YAML to match the project style guide.
  • Backend developers debugging YAML config files where indentation errors cause silent misconfigurations.
  • Students learning YAML structure by seeing how their input is re-serialized by the parser.

Example Input and Output

An inconsistently indented Kubernetes-style YAML config is reformatted with clean 2-space indentation.

Messy YAML input
name: my-app
version: "1.0"
server:
  host: localhost
  port: 8080
database:
    host: db.example.com
    port: 5432
    name: mydb
features:
  - auth
  - logging
  - metrics
Formatted YAML output
name: my-app
version: '1.0'
server:
  host: localhost
  port: 8080
database:
  host: db.example.com
  port: 5432
  name: mydb
features:
  - auth
  - logging
  - metrics

Privacy

All YAML parsing and formatting runs in your browser via js-yaml. No data is sent to any server.

YAML 1.2 note

js-yaml uses YAML 1.2 rules. Values like "on", "off", "yes", "no" are treated as strings, not booleans, which matches modern tools like Kubernetes and GitHub Actions.

Frequently Asked Questions

Why does my string value change quoting style after formatting?
The YAML serialiser picks the most readable quoting style for each value. Plain strings stay unquoted, strings with special characters get single quotes, and strings containing single quotes get double quotes. The value itself doesn't change — only the representation.
What does "Sort Keys" do?
Sort Keys alphabetises all object keys at every level of nesting. This is useful for consistent diffs in version control when multiple people edit the same YAML file.
Why does my YAML fail to format?
YAML is whitespace-sensitive. Common errors include mixing tabs and spaces, incorrect indentation of nested keys, unquoted special characters like : or #, and missing closing quotes. The error message shows the line and column where parsing failed.
Does formatting change my data?
No. The formatter parses your YAML into a data structure and re-serialises the same structure. The output is semantically identical to the input — only whitespace and quoting style may differ.
Is my YAML data sent to a server?
No. All parsing and formatting runs in your browser using the js-yaml library. Your data never leaves your device.
Can I use this for Kubernetes, Docker Compose, or GitHub Actions YAML?
Yes. The formatter handles all standard YAML including multi-document files, anchors and aliases, and the subset of YAML used by Kubernetes, Docker Compose, and GitHub Actions.

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