YAML ↔ JSON Converter

What YAML and JSON are used for

YAML and JSON both represent the same kinds of data — objects, arrays, strings, numbers, booleans, and null — just with different syntax. YAML is common in configuration files (Docker Compose, Kubernetes, CI/CD pipelines, GitHub Actions) because it's easier for humans to read and write by hand. JSON is the standard for APIs and most programming languages' native data interchange, since it's simpler to parse and has no ambiguity around whitespace. Developers frequently need to convert between the two — copying a config into an API payload, or turning an API response into a more readable config file.

How to use this converter

Paste or upload a YAML or JSON file, and the converted result appears on the other side instantly as you type. Use the swap button to reverse direction, choose 2 or 4-space indentation for the output, and copy or download the result when you're done. Everything happens in your browser — nothing you paste or upload is sent anywhere.

What gets preserved in the conversion

Nested objects and arrays, strings, numbers, booleans, and null values all convert cleanly between formats, since both YAML and JSON represent the same underlying data types. One thing to watch for: YAML supports some features JSON doesn't have a native equivalent for, like comments and multiple documents in one file (separated by `---`) — converting YAML with comments to JSON will drop the comments, since JSON has no way to represent them.

Common mistakes

The most common YAML mistake is inconsistent indentation — YAML is whitespace-sensitive, and mixing tabs and spaces (or using the wrong number of spaces) is one of the most frequent sources of parse errors. The most common JSON mistake when hand-editing is a trailing comma after the last item in an object or array, which many other languages tolerate but strict JSON parsers reject outright. This tool shows the parser's actual error message when something doesn't parse, rather than failing silently, so you can find and fix the exact issue.