JSON to YAML Converter — Free, Instant & Browser-Based

PyPython — Using PyYAML

# Install: pip install pyyaml
import json
import yaml

# Load JSON string
json_data = '{"name": "my-app", "replicas": 3, "enabled": true}'

# Parse JSON → Python dict → YAML string
python_dict = json.loads(json_data)
yaml_output = yaml.dump(python_dict, default_flow_style=False, allow_unicode=True)

print(yaml_output)
# Output:
# enabled: true
# name: my-app
# replicas: 3

# From file to file
with open('config.json', 'r') as f:
    data = json.load(f)

with open('config.yaml', 'w') as f:
    yaml.dump(data, f, default_flow_style=False, sort_keys=False)

JSJavaScript / Node.js — Using js-yaml

// Install: npm install js-yaml
const yaml = require('js-yaml');

// Convert JSON string to YAML
const jsonData = '{"name": "my-app", "replicas": 3, "enabled": true}';
const parsed = JSON.parse(jsonData);
const yamlOutput = yaml.dump(parsed, { indent: 2, lineWidth: -1 });

console.log(yamlOutput);
// Output:
// name: my-app
// replicas: 3
// enabled: true

// From file to file (Node.js)
const fs = require('fs');
const jsonObj = JSON.parse(fs.readFileSync('config.json', 'utf8'));
fs.writeFileSync('config.yaml', yaml.dump(jsonObj, { indent: 2 }));

CLICommand Line — Using yq or Python one-liner

# Using yq (install: brew install yq  or  snap install yq)
cat config.json | yq -P '.' > config.yaml

# Python one-liner (no install needed)
python3 -c "import sys,json,yaml; print(yaml.dump(json.load(sys.stdin)))" < config.json

# Using npx (no global install needed)
npx -y js-yaml config.json

Multiline Strings — Block Scalars

JSON requires \n escape sequences for multiline text. YAML supports native block scalars — far more readable for shell scripts, SQL queries, or long config values.

{
  "script": "#!/bin/bash\necho start\nnpm install\nnpm run build"
}

script: |
  #!/bin/bash
  echo start
  npm install
  npm run build

| (literal block) preserves newlines exactly. > (folded block) collapses newlines to spaces — useful for long prose strings.

Anchors & Aliases — Eliminate Repetition

YAML anchors (&name) let you define a block once and reference it multiple times with aliases (*name). This is critical for Kubernetes configurations with shared resource limits or environment variables.

# Define once with anchor
defaults: &defaults
  replicas: 2
  memory: "256Mi"
  cpu: "100m"

# Reuse with alias — no repetition
production:
  <<: *defaults
  replicas: 5      # override just this value

staging:
  <<: *defaults    # inherits replicas: 2, memory, cpu