UlvixorJSON to YAML and YAML to JSON Converter
Convert between JSON and YAML in both directions, with clear error validation for each format. Everything runs in your browser, with no data ever uploaded to a server.
How it works
- Choose the tab for the conversion you need: JSON to YAML or YAML to JSON.
- Paste or type your content into the input panel (or use the built-in example).
- The tool validates the input format and shows a clear error if it isn't valid.
- The result updates instantly in the output panel, ready to copy.
- Copy the result or download it as a .yaml or .json file, as appropriate.
Use cases
- Convert a YAML configuration file (for example from Docker Compose or Kubernetes) to JSON for processing with code.
- Turn an API's JSON response into YAML for a configuration file.
- Migrate configuration files between tools that use different formats.
- Visually review and compare the same data structure in both JSON and YAML.
Use cases
- Convert a YAML configuration file (for example from Docker Compose or Kubernetes) to JSON for processing with code.
- Turn an API's JSON response into YAML for a configuration file.
- Migrate configuration files between tools that use different formats.
- Visually review and compare the same data structure in both JSON and YAML.
Common mistakes
- Expecting comments from the original YAML to be preserved when converting to JSON.JSON doesn't support comments, so any comment present in the YAML is lost in the conversion; there's no way around this given JSON's format.
- Pasting several YAML documents separated by --- and expecting them to convert together.The tool processes a single YAML document at a time. If your file has multiple documents separated by '---', convert each one separately.
- Trying to convert invalid JSON (single quotes, a trailing comma) to YAML.The JSON must be valid before converting; the tool shows js-yaml's exact error message so you can fix it first.
Frequently asked questions
No. Conversion between JSON and YAML happens entirely in your browser using the js-yaml library. Your content never leaves your device.
The tool shows an error message describing the problem it found, so you can fix your JSON or YAML before trying to convert it again.
No. JSON doesn't support comments, so any comments in the original YAML are lost when converting to JSON. Converting from JSON to YAML doesn't generate new comments either.
Standard YAML types are supported: strings, numbers, booleans, nulls, lists, and nested maps, including multi-level structures.
The tool processes one YAML document at a time. If your file has several documents separated by '---', convert them one by one.
Alternatives
With Node.js you can use the js-yaml library (the same one this tool uses) or yq from the terminal to convert in both directions. This tool lets you do it with nothing to install and see the result instantly.