YAML Formatter

Format and validate YAML with 2-space or 4-space indentation.

Input132 chars
Output
paste YAML and click Format

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Documentation

What is YAML Formatter?

YAML ("YAML Ain't Markup Language") is the format behind most CI configs, Kubernetes manifests, and application config files. This tool re-indents and validates YAML documents.

How it works

The input is parsed with js-yaml's loader, then dumped back out with a fixed indent width. Parse errors include the exact line and column from the underlying mark.

Spec

YAML 1.2 Specification

Frequently Asked Questions

What does the YAML Formatter do?▾

It parses your YAML, then re-serializes it with consistent indentation (2 or 4 spaces), catching syntax errors along the way.

Why is YAML sensitive to indentation?▾

Unlike JSON, YAML uses indentation itself to represent nesting — there are no braces or brackets, so inconsistent spacing changes the meaning of the document.

What does Minify do for YAML?▾

It re-emits the document in flow style — the JSON-like {}/[] syntax YAML also supports — producing a compact, single-block representation of the same data.

What causes a YAMLException?▾

The most common causes are mixing tabs and spaces for indentation, an unquoted string that looks like a special value (e.g. `no` parsing as boolean false), or a missing colon after a key.

Does this handle multi-document YAML files?▾

This tool formats a single YAML document. Files with multiple documents separated by --- should be split first.

Is my YAML uploaded anywhere?▾

No — parsing and formatting run entirely in your browser via js-yaml.