YAML ⇄ JSON Converter

Convert between YAML and JSON formats instantly with optional sorting and custom indentation.

Overview

YAML ⇄ JSON Converter is a bidirectional tool that seamlessly transforms data between YAML and JSON formats. Perfect for developers working with configuration files, APIs, and infrastructure as code. Features include key sorting, customizable indentation, and real-time validation.

Features

🔄 Bidirectional Conversion

• YAML → JSON - Convert YAML to JSON format
• JSON → YAML - Convert JSON to YAML format
• One-click mode switching
• Sample data for quick testing
• Preserves data structure

✅ Smart Validation

• Real-time syntax checking
• Detailed error messages
• Catches format issues
• Helpful error locations
• Auto-detection of problems

⚙️ Customization Options

• Indentation: 2, 4, or 8 spaces
• Sort Keys: Alphabetical recursive sorting
• Line Width: Optimized for readability
• Format to your preference
• Match your coding style

⚡ Performance

• Instant conversion
• Client-side processing
• No server uploads
• Handles large files
• Smooth operation

📋 Quick Actions

• Copy output to clipboard
• Load sample data
• Clear all fields
• Switch modes instantly
• Character count display

🔒 Privacy First

• All processing in browser
• No data sent to servers
• No storage or logging
• Works offline
• Completely secure

How to Use

Basic Conversion

YAML to JSON:

1. Click YAML → JSON button
2. Paste YAML in left textarea
3. Click Convert button
4. JSON appears in right textarea
5. Click Copy to save result

JSON to YAML:

1. Click JSON → YAML button
2. Paste JSON in left textarea
3. Click Convert button
4. YAML appears in right textarea
5. Click Copy to save result

Quick Start with Sample

1. Click Load Sample button
2. Sample data appears in input
3. Click Convert to see result
4. Experiment with options

Using Options

Sort Keys:

1. Check Sort Keys checkbox
2. Click Convert
3. All object keys sorted alphabetically
4. Sorting is recursive (nested objects too)

Change Indentation:

1. Select 2, 4, or 8 from dropdown
2. Click Convert
3. Output uses selected indentation
4. Affects both JSON and YAML

Switching Modes

1. Click YAML → JSON or JSON → YAML
2. Input label updates to match
3. Output clears automatically
4. Ready for new conversion

Clearing Data

1. Click Clear button
2. Input and output cleared
3. Errors reset
4. Start fresh

Use Cases

1. Kubernetes Configuration

# YAML (k8s-config.yaml)
apiVersion: v1
kind: Service
metadata:
  name: my-service
  namespace: production
spec:
  selector:
    app: MyApp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 9376
  type: LoadBalancer

# Convert to JSON for processing
{
  "apiVersion": "v1",
  "kind": "Service",
  "metadata": {
    "name": "my-service",
    "namespace": "production"
  },
  "spec": {
    "selector": {
      "app": "MyApp"
    },
    "ports": [
      {
        "protocol": "TCP",
        "port": 80,
        "targetPort": 9376
      }
    ],
    "type": "LoadBalancer"
  }
}

// Use cases:
// - Validate k8s configs
// - Convert for API calls
// - Generate JSON schemas
// - Testing configurations

2. Docker Compose Conversion

# docker-compose.yml
version: '3.8'
services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./html:/usr/share/nginx/html
    environment:
      - NGINX_HOST=localhost
      - NGINX_PORT=80
  db:
    image: postgres:13
    environment:
      POSTGRES_DB: myapp
      POSTGRES_USER: admin
      POSTGRES_PASSWORD: secret

# Convert to JSON for programmatic parsing
# Useful for:
// - CI/CD pipelines
// - Config management tools
// - Docker API interactions
// - Automated deployments

3. GitHub Actions Workflow

# .github/workflows/ci.yml
name: CI Pipeline
on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Run tests
        run: npm test
      - name: Upload coverage
        uses: codecov/codecov-action@v1

# Convert to JSON for:
// - Validation tools
// - Workflow analyzers
// - Documentation generation
// - Custom processing

4. API Response Transformation

// API returns JSON
{
  "user": {
    "id": 123,
    "name": "John Doe",
    "email": "john@example.com",
    "preferences": {
      "theme": "dark",
      "notifications": true
    }
  }
}

# Convert to YAML for config file
user:
  id: 123
  name: John Doe
  email: john@example.com
  preferences:
    theme: dark
    notifications: true

# Benefits:
# - More readable configs
# - Comments support in YAML
# - Less verbose
# - Human-friendly

5. Configuration Migration

# Old config format (YAML)
database:
  host: localhost
  port: 5432
  credentials:
    user: admin
    password: secret
cache:
  redis:
    host: cache.example.com
    ttl: 3600
features:
  auth: true
  payments: false

# Convert to JSON for new system
# Then transform with custom logic
# Finally convert back to YAML
# Migration workflow complete!

6. Infrastructure as Code

# Terraform-like YAML
resources:
  - type: aws_instance
    name: web_server
    properties:
      ami: ami-12345678
      instance_type: t2.micro
      tags:
        Name: WebServer
        Environment: Production
  - type: aws_s3_bucket
    name: data_bucket
    properties:
      bucket: my-data-bucket
      acl: private

# Convert to JSON for:
// - Template validation
// - Resource planning
// - Cost estimation tools
// - Deployment automation

Format Comparison

YAML Syntax

# Comments supported
person:
  name: John Doe
  age: 30
  active: true
  tags:
    - developer
    - admin
  address:
    city: New York
    zip: "10001"

YAML Features:

• Comments with #
• No quotes needed (usually)
• Indentation-based hierarchy
• Lists with -
• More human-readable
• Less verbose
• Multi-line strings easy

JSON Syntax

{
  "_comment": "Comments not supported natively",
  "person": {
    "name": "John Doe",
    "age": 30,
    "active": true,
    "tags": [
      "developer",
      "admin"
    ],
    "address": {
      "city": "New York",
      "zip": "10001"
    }
  }
}

JSON Features:

• Strict syntax rules
• Double quotes required
• Comma-separated
• Braces {} for objects
• Brackets [] for arrays
• Machine-readable
• Widely supported

When to Use Each

Use Case	Format	Reason
Config Files	YAML	Comments, readability
APIs	JSON	Universal support
Human Editing	YAML	Less verbose, clearer
Machine Processing	JSON	Strict, predictable
CI/CD	YAML	Comments, multi-line
Web APIs	JSON	Native JS support
Documentation	YAML	Readable examples
Data Exchange	JSON	Language-agnostic

Advanced Features

Key Sorting

What It Does:

• Sorts all object keys alphabetically
• Recursive (applies to nested objects)
• Helps with:
  • Version control diffs
  • Finding duplicates
  • Consistent formatting
  • Easier comparison

Example:

# Input (unsorted)
person:
  email: john@example.com
  age: 30
  name: John
  address:
    zip: 10001
    city: New York

# Output (sorted)
person:
  address:
    city: New York
    zip: 10001
  age: 30
  email: john@example.com
  name: John

⚠️ Warning: May alter semantics if key order matters (rare)

Indentation Control

Available Options:

• 2 spaces - Compact, common standard
• 4 spaces - More visible, Python-style
• 8 spaces - Very visible, less common

Impact:

# 2-space indent
user:
  name: John
  settings:
    theme: dark

# 4-space indent
user:
    name: John
    settings:
        theme: dark

# 8-space indent
user:
        name: John
        settings:
                theme: dark

Recommendation: Use 2 spaces for most cases (standard)

Sample Data

YAML Sample:

name: DevApps
features:
  - base64
  - json
  - yaml
meta:
  version: 1
  active: true

JSON Sample:

{
  "name": "DevApps",
  "features": ["base64", "json", "yaml"],
  "meta": {
    "version": 1,
    "active": true
  }
}

Technical Details

Conversion Process

YAML → JSON:

1. Parse YAML using js-yaml library
2. Validate structure
3. Optional: Sort keys recursively
4. Stringify to JSON with indentation
5. Display formatted result

JSON → YAML:

1. Parse JSON using JSON.parse()
2. Validate structure
3. Optional: Sort keys recursively
4. Dump to YAML with formatting
5. Display formatted result

Supported Features

Feature	YAML	JSON
Objects	✅	✅
Arrays	✅	✅
Strings	✅	✅
Numbers	✅	✅
Booleans	✅	✅
Null	✅	✅
Comments	✅	❌
Multi-line	✅	⚠️
Anchors/Refs	✅	❌
Dates	✅	⚠️

Notes:

• JSON comments: Not supported (use _comment key)
• Multi-line in JSON: Use \n escaping
• YAML anchors: Converted to duplicated data
• Dates: Converted to ISO strings

Performance

Data Size	Conversion Time
< 1 KB	< 10ms
1-10 KB	10-50ms
10-100 KB	50-200ms
100KB-1MB	200ms-1s
> 1 MB	1s+

Line Width

YAML output uses 120-character line width for optimal readability while preventing excessive wrapping.

Troubleshooting

"Conversion failed" Error

Problem: Generic error during conversion

YAML → JSON Solutions:

1. Check Indentation - Must be consistent (2 or 4 spaces)
2. Remove Tabs - YAML doesn't allow tabs
3. Fix Quotes - Match opening/closing quotes
4. Check Colons - Space after colon required
5. Validate Lists - Proper - alignment

JSON → YAML Solutions:

1. Check Commas - No trailing commas
2. Use Double Quotes - Not single quotes
3. Balance Brackets - Every { needs }, [ needs ]
4. Remove Comments - JSON doesn't support comments

Common YAML Errors

# ❌ Wrong - Tab character
person:
	name: John  # Tab used!

# ✅ Correct - Spaces
person:
  name: John

# ❌ Wrong - Inconsistent indentation
person:
  name: John
    age: 30  # Too much indent

# ✅ Correct
person:
  name: John
  age: 30

# ❌ Wrong - No space after colon
person:
  name:John

# ✅ Correct
person:
  name: John

Common JSON Errors

// ❌ Wrong - Trailing comma
{
  "name": "John",
  "age": 30,
}

// ✅ Correct
{
  "name": "John",
  "age": 30
}

// ❌ Wrong - Single quotes
{
  'name': 'John'
}

// ✅ Correct
{
  "name": "John"
}

// ❌ Wrong - Comments
{
  // This is a comment
  "name": "John"
}

// ✅ Correct
{
  "_comment": "Use a key for comments",
  "name": "John"
}

Sort Keys Not Working

Problem: Keys still in original order

Solution:

1. Ensure checkbox is checked
2. Click Convert again
3. Refresh page if needed
4. Check if keys are sortable (not arrays)

Output Not Copying

Problem: Copy button doesn't work

Solution:

1. Check browser permissions
2. Manually select and copy (Ctrl/Cmd+C)
3. Try different browser
4. Download output instead

Indentation Looks Wrong

Problem: Output indentation unexpected

Solution:

1. Check indent dropdown setting
2. Convert again after changing
3. Verify input format is correct
4. Some editors auto-format (may override)

YAML Special Features

Multi-line Strings

Literal Style (|):

description: |
  This is a multi-line
  string that preserves
  line breaks.

Folded Style (>):

description: >
  This is a multi-line
  string that folds into
  a single line.

Anchors & References

# Define anchor
defaults: &defaults
  timeout: 30
  retries: 3

# Reference anchor
production:
  <<: *defaults
  host: prod.example.com

development:
  <<: *defaults
  host: dev.example.com

Note: When converted to JSON, anchors are resolved (duplicated)

Comments

# This is a comment
person:
  name: John  # Inline comment
  # Another comment
  age: 30

Note: Comments lost when converting to JSON

Type Coercion

# YAML automatically detects types
string: hello
number: 42
float: 3.14
boolean: true
null_value: null
date: 2025-11-26

Best Practices

✅ Do's

1. Validate Before Converting

   • Ensure input is valid format
   • Fix errors first
   • Use linters when available

2. Use Consistent Indentation

   • Stick to 2 or 4 spaces
   • Never mix tabs and spaces
   • Configure editor for spaces

3. Sort Keys for Version Control

   • Easier diffs
   • Consistent formatting
   • Reduce merge conflicts

4. Add Comments in YAML

   • Document configuration
   • Explain complex values
   • Help future maintainers

5. Keep Backups

   • Save original files
   • Test conversions
   • Verify output before using

❌ Don'ts

1. Don't Use Tabs in YAML

   • YAML spec forbids tabs
   • Use spaces only
   • Configure editor properly

2. Don't Rely on Key Order

   • Objects are unordered in JSON
   • May change between versions
   • Use arrays if order matters

3. Don't Lose Comments

   • Comments removed in JSON
   • Document before converting
   • Keep YAML source files

4. Don't Convert Without Testing

   • Verify output works
   • Test in target system
   • Check edge cases

5. Don't Forget to Copy

   • Easy to lose converted data
   • Copy before clearing
   • Save important conversions

Integration Examples

Node.js Script

const yaml = require('js-yaml');
const fs = require('fs');

// YAML to JSON
const yamlContent = fs.readFileSync('config.yaml', 'utf8');
const jsonData = yaml.load(yamlContent);
fs.writeFileSync('config.json', JSON.stringify(jsonData, null, 2));

// JSON to YAML
const jsonContent = fs.readFileSync('data.json', 'utf8');
const yamlData = yaml.dump(JSON.parse(jsonContent));
fs.writeFileSync('data.yaml', yamlData);

Python Script

import yaml
import json

# YAML to JSON
with open('config.yaml', 'r') as yaml_file:
    data = yaml.safe_load(yaml_file)
    with open('config.json', 'w') as json_file:
        json.dump(data, json_file, indent=2)

# JSON to YAML
with open('data.json', 'r') as json_file:
    data = json.load(json_file)
    with open('data.yaml', 'w') as yaml_file:
        yaml.dump(data, yaml_file)

CI/CD Pipeline

# GitHub Actions example
- name: Convert YAML to JSON
  run: |
    npm install -g js-yaml
    js-yaml config.yaml > config.json
    
- name: Validate JSON
  run: |
    cat config.json | jq empty

Frequently Asked Questions

Can I convert large files?

Yes, but very large files (> 1MB) may take longer. The tool handles most config files easily.

Will my YAML comments be preserved?

No, comments are lost when converting to JSON (JSON doesn't support comments). Keep your original YAML file.

Does it support YAML 1.2?

The tool uses js-yaml which primarily supports YAML 1.2 with some 1.1 features.

Can I convert multiple files at once?

Currently one file at a time. For batch processing, use command-line tools or scripts.

Are anchors and references supported?

Yes, YAML anchors are parsed, but they're resolved (duplicated) in JSON output.

Does it work offline?

Yes! All processing is client-side. Works without internet after loading the page.

How do I handle special characters?

Both formats support UTF-8. Special characters are automatically escaped properly.

Can I customize the YAML style?

Current version uses default style. Flow style and other options not yet configurable.

Will sorting keys break my data?

Generally no, but if your application relies on key order (uncommon), avoid sorting.

How accurate is the conversion?

100% accurate for standard data types. Complex YAML features may have edge cases.

Privacy & Security

✅ Completely Private

• All processing in your browser
• No server uploads
• No network requests
• No data logging
• Works offline

✅ Safe for Sensitive Data

• Convert credentials safely
• Process API configs securely
• No external access
• No data retention

✅ No Storage

• No localStorage
• No cookies
• No session data
• Data cleared on close
• Completely ephemeral

Browser Compatibility

Works in all modern browsers:

• ✅ Chrome / Edge (Chromium) 90+
• ✅ Firefox 88+
• ✅ Safari 14+
• ✅ Opera 76+
• ✅ Mobile browsers

Related Tools

• JSON Formatter - Format and beautify JSON
• JSON Minifier - Compress JSON for production
• JSON Tree Viewer - Visualize JSON structure
• Base64 Encoder - Encode/decode Base64 data

Tips & Tricks

Quick Workflow

1. Load sample to learn format
2. Clear and paste your data
3. Choose options before converting
4. Copy output immediately
5. Verify in target system

Configuration Management

1. Keep source files in YAML (readable)
2. Convert to JSON for deployment
3. Use sort keys for version control
4. Document with YAML comments

Debugging

1. Convert to other format to validate
2. Use tree viewer for complex data
3. Format before troubleshooting
4. Check character counts for issues

Learning

1. Start with samples
2. Experiment with options
3. Compare both formats
4. Practice with real configs

Standards

Follows specifications:

• JSON: RFC 8259 - The JSON Data Interchange Format
• YAML: YAML 1.2 - 3rd Edition
• js-yaml: Industry-standard parser

Credits

Built with js-yaml library for robust YAML parsing and generation. Supports most YAML 1.2 features with excellent JSON compatibility.