Convert JSON to YAML from Command Line [CLI Guide]

Method 1: Using yq (Recommended)

yq is the best CLI tool for JSON to YAML conversion. It's fast, handles streaming, and supports complex queries similar to jq.

Install yq

# macOS (Homebrew)
brew install yq

# Ubuntu/Debian
sudo apt-get install yq

# Or download binary directly
sudo wget https://github.com/mikefarah/yq/releases/latest/download/yq_linux_amd64 -O /usr/bin/yq
sudo chmod +x /usr/bin/yq

# Windows (Chocolatey)
choco install yq

# Verify installation
yq --version

yq Convert JSON to YAML

# Convert JSON file to YAML
yq -P input.json > output.yaml

# Convert and print to stdout
yq -P input.json

# Convert from stdin
cat input.json | yq -P

# With pretty output (default)
yq -P --indent 2 input.json > output.yaml

Method 2: Using Python (No Install Required)

Python is often pre-installed on Linux and macOS. Use this one-liner to convert JSON to YAML from the command line. For more comprehensive Python examples, see our Python JSON to YAML guide.

# JSON to YAML (one-liner)
python -c "import json,yaml,sys; print(yaml.dump(json.load(sys.stdin)))" < input.json > output.yaml

# More readable version with safe_dump
python3 -c "
import json, yaml, sys
data = json.load(sys.stdin)
print(yaml.safe_dump(data, default_flow_style=False))
" < input.json > output.yaml

# YAML to JSON (reverse)
python -c "import json,yaml,sys; print(json.dumps(yaml.safe_load(sys.stdin), indent=2))" < input.yaml > output.json

Method 3: Using Ruby

Ruby has YAML and JSON libraries built-in, making it perfect for quick conversions without installing additional packages:

# JSON to YAML (Ruby one-liner)
ruby -ryaml -rjson -e "puts YAML.dump(JSON.parse(STDIN.read))" < input.json > output.yaml

# YAML to JSON
ruby -ryaml -rjson -e "puts JSON.pretty_generate(YAML.load(STDIN.read))" < input.yaml > output.json

Method 4: Using jq + yq

jq is excellent for JSON transformations but cannot output YAML. Combine it with yq for powerful pipelines:

# Basic jq to yq pipeline
cat input.json | jq '.' | yq -P > output.yaml

# Transform JSON, then convert to YAML
cat input.json | jq '.items[] | select(.active)' | yq -P > filtered.yaml

# Extract specific fields and convert
jq '{name: .name, version: .version}' package.json | yq -P

Tool Comparison Table

* Python needs PyYAML: pip install pyyaml

Convert Multiple Files

Convert all JSON files in a directory to YAML using a bash loop. This is especially useful for managing configuration files or DevOps workflows:

# Batch convert all JSON files to YAML (Linux/macOS)
for f in *.json; do
  yq -P "$f" > "${f%.json}.yaml"
  echo "Converted: $f -> ${f%.json}.yaml"
done

# Using find for recursive conversion
find . -name "*.json" -exec sh -c 'yq -P "$1" > "${1%.json}.yaml"' _ {} \;

# Windows PowerShell
Get-ChildItem *.json | ForEach-Object {
  yq -P $_.FullName > ($_.BaseName + ".yaml")
}

YAML to JSON CLI

Convert YAML back to JSON using the same tools:

# yq: YAML to JSON
yq -o json input.yaml > output.json

# Python: YAML to JSON
python -c "import json,yaml,sys; print(json.dumps(yaml.safe_load(sys.stdin), indent=2))" < input.yaml > output.json

# Ruby: YAML to JSON
ruby -ryaml -rjson -e "puts JSON.pretty_generate(YAML.load(STDIN.read))" < input.yaml > output.json