YAML Formatter

Format and validate YAML, or convert it to JSON and back.

YAML Input

Formatted YAML

How to use YAML Formatter

Choose Format / Validate, YAML → JSON, or JSON → YAML.
Paste your input.
The formatted or converted result appears automatically — copy it, or fix the error shown if it's invalid.

→ validate the JSON side on its own

Frequently asked questions

Does this validate my YAML is correct?

Yes — if the YAML can't be parsed, the parser's exact error message (including the line it choked on) is shown instead of a result, which is usually enough to spot a bad indent or a stray colon.

Does converting YAML to JSON lose anything?

YAML-specific features with no JSON equivalent — comments, anchors/aliases (reused blocks), and multi-document files — don't survive the conversion, since JSON has no way to represent them. Plain key-value data converts cleanly.

Is this processed on a server?

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

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