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 live tool at freeq.one/tools/yaml-formatter — part of the FreeQ.One suite of free online tools.