JSON and YAML Converter

JSON and YAML Converter

Convert JSON to YAML or YAML to JSON. Powered by the js-yaml library loaded from cdnjs; conversion itself runs in your browser.

The JSON and YAML Converter moves data between the two formats developers juggle daily. JSON is the language of APIs and web data; YAML is the language of configuration files, from Docker Compose to GitHub Actions to Kubernetes. Being able to flip a snippet from one to the other, reliably and instantly, saves constant manual retyping.

This tool uses the well-known js-yaml library, loaded from the cdnjs content delivery network and verified before use, to do proper, full-featured conversion in both directions. YAML anchors, multi-line strings, nested lists, and typed values like numbers and booleans are parsed the way real YAML tools parse them, because the same library powers this page.

Only the library file comes from the network. Your data itself is converted locally in your browser and is never uploaded anywhere, so configuration files with internal hostnames and test data stay on your machine.

How to use

  1. Paste JSON or YAML into the input box.
  2. Click JSON to YAML or YAML to JSON, matching your input.
  3. Review the converted result below.
  4. Copy the result for use in your project or config file.
  5. If an error appears, it names the parsing problem to fix.

Frequently asked questions

Why use a library instead of a simple converter?

YAML is deceptively complex, with indentation rules, anchors, and many scalar styles. A full library like js-yaml handles those cases correctly, where a quick hand-rolled converter would silently produce wrong output.

Does YAML keep my data types?

Mostly yes. Strings, numbers, booleans, nulls, arrays, and objects convert naturally. Very unusual YAML tags that have no JSON equivalent may be simplified, and the converter reports errors instead of guessing.

Do I need an internet connection?

Yes, once, to load the js-yaml library file from cdnjs. After it loads, all conversion happens offline in your browser.

Is my data uploaded?

No. Only the library script is downloaded. Your input never leaves your device.