Free JSON to YAML Converter — Also Converts YAML to JSON (2026)

JSON vs YAML — Key Differences (2026 Guide)

How to Use — Step by Step

1. 1
   Choose direction: Select JSON → YAML or YAML → JSON using the mode tabs.
2. 2
   Paste or type: Enter your JSON or YAML in the left panel. Output updates live as you type.
3. 3
   Load a sample: Click Load Sample to see a pre-built configuration example with nested objects and arrays.
4. 4
   Review output: Check the right panel. If there's a red error, fix the syntax shown in the error banner.
5. 5
   Copy or Download: Use Copy to grab the output, or Download to save as .yaml or .json file.
6. 6
   Round-trip: Click Swap to use the output as new input — useful for verifying conversion accuracy.

Frequently Asked Questions

• What is YAML and how does it differ from JSON?

  YAML (YAML Ain't Markup Language) is a human-friendly data serialization format designed to be readable. Unlike JSON, YAML uses indentation instead of braces, allows comments (# ...), does not require quotes around most strings, and supports multi-line strings. JSON is a strict subset of JavaScript syntax, while YAML is a superset of JSON — all valid JSON is also valid YAML. YAML is popular in configuration files (Kubernetes, GitHub Actions, Docker Compose, Ansible), while JSON dominates APIs.

• When should I use YAML instead of JSON?

  Use YAML for configuration files that humans need to read and edit — Kubernetes manifests, CI/CD pipelines, Ansible playbooks, and Docker Compose files all use YAML. Use JSON for API payloads, data exchange between services, and anywhere a strict machine-readable format is required. YAML's support for comments makes it better for configs where you need to explain settings to other developers.

• Does the converted YAML preserve all JSON data types?

  Yes. JSON strings, numbers, booleans (true/false), null, arrays, and objects are all preserved with proper YAML equivalents. Strings that look like numbers or booleans are automatically quoted to prevent ambiguity. Nested objects and arrays are expressed using YAML's indented block style, which is fully equivalent to the original JSON structure.

• Can this tool convert YAML back to JSON?

  Yes. Use the YAML → JSON mode. The tool parses standard YAML (block mappings, block sequences, scalar types) and converts to formatted JSON. It handles common YAML patterns: key-value pairs, nested objects, arrays with - prefix, and auto-typed scalars (numbers, booleans, null). Comments are ignored. Use the Swap button to do round-trip conversions.

• What YAML features are NOT supported?

  This tool handles JSON-compatible YAML — the subset of YAML that maps directly to JSON data types. Unsupported YAML features include: anchors and aliases (&anchor, *alias), merge keys (<<), multi-document files (---), block scalars (| and >), complex mapping keys, and YAML tags (!!str, !!int). These are rarely needed when converting to/from JSON.

• Why are some string values quoted in the YAML output?

  YAML auto-types unquoted scalars — for example, 'true', 'false', 'null', 'yes', 'no', and strings that look like numbers would be parsed as non-string types if unquoted. To preserve the original JSON string type, this tool automatically wraps ambiguous strings in double quotes. This ensures the YAML round-trips correctly back to the same JSON structure.

• What is the indentation style used in the YAML output?

  The output uses 2-space indentation, which is the most common YAML convention and the default for tools like Prettier, yaml-language-server, and most Kubernetes/CI tooling. This is not configurable in the current version but 2 spaces is universally compatible with all YAML parsers.

• Can I use this to convert Kubernetes or Docker Compose JSON to YAML?

  Yes. If you have a Kubernetes resource in JSON format (e.g., from kubectl get deployment myapp -o json), paste it into the JSON input panel and click JSON → YAML. The output is valid Kubernetes YAML you can apply directly with kubectl apply -f. Similarly for Docker Compose: convert compose.json to compose.yaml for use with Docker Compose v2+.

• How does the tool handle JSON arrays of objects in YAML?

  JSON arrays become YAML block sequences. Each array item is prefixed with '- '. Objects inside an array use the compact notation where the first key appears on the same line as the dash, and subsequent keys are indented by 2 additional spaces. This is the standard YAML list-of-maps format used in Kubernetes, Ansible, and GitHub Actions.

• Is my YAML/JSON data private?

  Yes. All conversion runs in your browser using JavaScript. Your YAML and JSON data are never sent to any server. You can disconnect from the internet after loading the page and the tool continues to work. This makes it safe for converting configuration files containing API keys, database credentials, or other sensitive settings.

• What happens if I paste invalid JSON in JSON→YAML mode?

  A red error banner appears below the output panel showing the exact JSON parse error from the JavaScript engine. The output area shows the error message in red. Fix the syntax error in your JSON (check for missing quotes, trailing commas, or unescaped characters) and the output will update automatically.

• Is this JSON to YAML converter free?

  Completely free, no account required, no usage limits. Both JSON→YAML and YAML→JSON conversions are included. Download output as .yaml or .json, copy to clipboard, and use the Swap button for round-trip conversions. All processing is browser-based — your configuration files stay private.