Free Online JSON ↔ YAML Converter
Convert YAML to JSON or JSON to YAML instantly, with clear error messages if the input isn't valid — no configuration needed either direction. It helps developers move configuration between YAML-based deployment files and JSON-based APIs or tooling.
JSON vs. YAML
JSON and YAML both represent the same kinds of structured data — objects/mappings, arrays/sequences, strings, numbers, booleans, and null — but with very different syntax. JSON uses braces, brackets, and quotes and is easy for machines to parse unambiguously. YAML uses indentation and minimal punctuation, making it more readable by hand, which is why it's the format of choice for configuration files (Kubernetes manifests, GitHub Actions workflows, Docker Compose files) even though APIs overwhelmingly use JSON.
How to convert between them
Choose a direction, paste your YAML or JSON into the input box, and click Convert. If the input isn't valid, the exact parsing error is shown instead of a blank or garbled result. Use Swap with output to immediately convert the result back, useful for verifying a round-trip conversion.
Common use cases
- Converting a Kubernetes or Docker Compose YAML file into JSON for use with a tool that only accepts JSON
- Turning an API's JSON response into more readable YAML for documentation or a config template
- Debugging a YAML config file by round-tripping it through JSON to spot subtle indentation or type issues
How to use JSON ↔ YAML Converter for related tasks
Choose the conversion direction, inspect the parsed result, and watch for YAML indentation or scalar-type edge cases.
Related tools: JSON ↔ TOML Converter, JSON Parser.
Frequently asked questions
Is my data uploaded anywhere when I convert it?
No — conversion runs entirely in your browser. Nothing you paste is ever sent to a server.
Why does my converted YAML look different from what I expected?
YAML has multiple valid ways to represent the same data (block style vs. flow style, quoted vs. unquoted strings) — the converter always produces block-style YAML with consistent 2-space indentation, which may differ stylistically from hand-written YAML even though the underlying data is identical.
What YAML features are supported?
Standard YAML 1.2/1.1 features: mappings, sequences, scalars, multi-line strings, comments (ignored on parse, since JSON has no comment equivalent), and common tags like dates and null. Anchors and aliases (YAML's way of reusing a value in multiple places) are resolved to their final values during conversion.
Can I convert a JSON array at the top level?
Yes — both directions support any valid JSON value at the top level, including arrays, not just objects.
Why did my YAML value change type after conversion?
YAML can infer booleans, numbers, and dates from plain text; quote values when their exact string representation matters.