YAML to JSON Converter.

Paste your YAML data or upload a .yaml/.yml file into the input area above, then click Convert. The parser reads YAML mappings, sequences, and scalars, and outputs a formatted JSON representation. Download the .json file or copy the output. All processing is client-side — your data never leaves your device.

Drag and drop your .yaml or .yml file onto the upload area, or click to browse. The converter handles nested structures, multi-line strings, and YAML-specific features (anchors, aliases are resolved). Click Copy to copy the JSON output or Download to save as a .json file.

YAML is best for configuration files (Docker, Kubernetes, Ansible, GitHub Actions) because it supports comments, is easy for humans to read and edit, and handles complex structures naturally. JSON is best for APIs, web apps, and data serialization because it parses faster, is universally supported, and has a stricter syntax that avoids ambiguity. Use YAML when humans are the primary author; use JSON when machines are the primary consumer.

YAML is a superset of JSON — any valid JSON is also valid YAML. YAML adds: comments (#), anchors and aliases (&ref / *ref) to avoid repetition, multi-line strings (| / >), and cleaner syntax without braces or quotes. JSON is stricter and faster to parse, making it better for high-throughput systems. YAML's flexibility can lead to subtle errors (e.g., Norway problem where no is parsed as false).

Install PyYAML: pip install pyyaml, then:
import yaml, json
with open('config.yaml') as f:
  data = yaml.safe_load(f)
with open('output.json', 'w') as f:
  json.dump(data, f, indent=2)
Use yaml.safe_load() instead of yaml.load() to avoid arbitrary code execution from untrusted YAML. For large files, consider ruamel.yaml which offers streaming parsing.

YAML is significantly more readable for humans — it uses indentation for structure (like Python), supports comments, and allows unquoted strings. JSON requires braces, brackets, and quotes on all keys, making it more verbose but also less ambiguous. A YAML file is typically 20-30% shorter than its JSON equivalent. For config files that developers edit by hand, YAML is the clear winner; for machine-generated data, JSON's strictness is an advantage.

Online: jsontofile.com (free, client-side, no limits). CLI: yq -P -oy input.json or python -c 'import yaml,json;print(yaml.dump(json.load(open("f.json"))))'. VS Code: install the YAML extension by Red Hat, open a JSON file, and use Ctrl+Shift+P → "Transform to YAML". Programmatic: js-yaml (JavaScript), PyYAML (Python), snakeyaml (Java). Our converter uses js-yaml and runs entirely in your browser.

The fastest way is the converter on this page — just paste your JSON and click Convert. For command-line use: yq -P -oy input.json > output.yaml. In VS Code, use the YAML extension's transform command. For programmatic conversion in JavaScript: import yaml from 'js-yaml'; const output = yaml.dump(JSON.parse(jsonString));