YAML Formatter & Validator — Format, Validate & Convert Onli
Format, validate, and convert YAML to/from JSON with a single click — auto-indented, error positions flagged, and one-click copy. 100% in your browser. This free online tool runs entirely in your browser — no data is ever uploaded to a server. How to Use 1. Paste YAML — messy, minified, or poorly indented — into the editor (or load a file / paste from clipboard). 2. Mode: Format — clean 2-space indented output; syntax errors flagged with the exact line & column. 3. Mode: Validate — pass/fail check with the precise error location before you commit or deploy. 4. Modes: YAML→JSON / JSON→YAML — convert between the two with a round-trip you can copy straight away. 5. History & pins — recent runs are saved locally; pin the ones you want to keep (max 10 pinned). Example Drop in a minified CI config and Format turns it into clean, consistent YAML; flip to Validate to confirm it parses, or switch to YAML→JSON to embed it in a pipeline that needs JSON. Also check out the ...