Format, validate, and beautify YAML online, and convert between YAML and JSON. Fix indentation, catch syntax errors, and normalize config with a spec-compliant YAML 1.2 engine.
YAML runs the modern infrastructure world — Kubernetes manifests, Docker Compose files, GitHub Actions workflows, and countless config files all use it. But YAML is famously sensitive to indentation, and a single misplaced space can break an entire deployment. This formatter parses your YAML, validates it, and re-emits it with clean, consistent indentation, so you can trust that what you are shipping is correct and tidy.
As you type or paste, the tool validates live and pinpoints the exact line of any syntax error — no more hunting through a file for a stray tab. Everything runs in your browser, so even config that contains sensitive values stays completely private.
Convert Between YAML and JSON
Because YAML and JSON describe the same kinds of data, moving between them is a constant need — you might receive a JSON API response and want it as a readable YAML config, or take a YAML file and feed it to a tool that only speaks JSON. This formatter does both directions with a single click, using a spec-compliant YAML 1.2 engine that correctly handles nested maps, sequences, multi-line strings, and typed values.
You can choose 2 or 4 space indentation, sort keys alphabetically for deterministic and diff-friendly output, upload a file instead of pasting, and copy or download the result. It is a fast, private, all-in-one YAML workbench.
How to use this YAML Formatter?
1
Choose Mode
Format YAML, or convert YAML → JSON or JSON → YAML.
2
Paste or Upload
Drop your YAML or JSON in, or upload a file. It is validated live.
3
Set Indentation
Pick 2 or 4 space indentation, and optionally sort keys.
4
Copy or Download
Grab the clean, formatted output with one click.
Frequently Asked Questions
Formatting parses your YAML and re-emits it with clean, consistent indentation and spacing. It normalises messy or hand-edited YAML into a tidy, standard layout, and in the process validates that the document is syntactically correct — catching indentation mistakes, which are the most common YAML error.
Yes. Alongside formatting, this tool converts YAML to JSON and JSON to YAML. YAML is a superset of JSON, so any valid JSON is also valid YAML, and the converter handles nested structures, arrays, and scalars in both directions.
The most common cause is inconsistent indentation — YAML uses spaces (never tabs) to denote structure, and mixing them breaks parsing. Other frequent issues are missing colons after keys, unclosed quotes, and using a tab character. The tool shows the exact line and reason so you can fix it quickly.
The tool uses a spec-compliant YAML 1.2 parser, which is the current standard used by Kubernetes, Docker Compose, GitHub Actions, and most modern tooling. It supports anchors, aliases, flow and block styles, multi-line strings, and typed scalars.
No. All parsing, formatting, and conversion happen in your browser. Your YAML and JSON never leave your device, so it is safe for private configuration and secrets.