Learn JSON, XML, YAML and TOML

{ } JSON - JavaScript Object Notation

JSON is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is the most widely used format for web APIs, mobile app communication, and software configuration files.

Key Features of JSON:

Simple Structure: Data is stored in clear key and value pairs, which makes it easy to read.
Works with Any Language: JSON is supported by almost all programming languages.
Lightweight: It uses less data and loads quickly.
Very Popular: JSON is the most commonly used format for REST APIs and web communication.

Data Types:

String - Text values in double quotes
Number - Whole or decimal numbers
Boolean - true or false
Array - Ordered list of values
Object - A collection of key-value pairs
null - Empty value

Example:

{
  "name": "Rahul Kumar",
  "age": 28,
  "isStudent": false,
  "skills": ["JavaScript", "Python", "React"],
  "address": {
    "city": "Mumbai",
    "state": "Maharashtra",
    "pincode": 400001
  },
  "projects": [
    {
      "title": "E-commerce Website",
      "status": "completed",
      "year": 2023
    },
    {
      "title": "Mobile App",
      "status": "in-progress",
      "year": 2024
    }
  ]
}

Common Use Cases:

REST API responses and requests
Configuration files (package.json, tsconfig.json)
Data storage and transfer
NoSQL databases (MongoDB)

</> XML - Extensible Markup Language

XML is a markup language used to store data in a structured and hierarchical format. It uses tags that look similar to HTML, but it allows you to create your own custom tags.

Key Features:

Self-Descriptive: Tags clearly describe the data they contain.
Hierarchical Structure: Data is organized in parent and child relationships.
Extensible: You can define your own custom tags.
Platform Independent: It can be used on any system or platform.

Syntax Rules:

Must have a root element
Tags are case-sensitive
Properly nested and closed
Attributes in quotes

Example:

<?xml version="1.0" encoding="UTF-8"?>
<employee>
  <name>Rahul Kumar</name>
  <age>28</age>
  <department id="IT-001">
    <name>Information Technology</name>
    <location>Mumbai</location>
  </department>
  <skills>
    <skill level="expert">JavaScript</skill>
    <skill level="intermediate">Python</skill>
    <skill level="expert">React</skill>
  </skills>
  <projects>
    <project status="completed">
      <title>E-commerce Website</title>
      <year>2023</year>
    </project>
  </projects>
</employee>

Common Use Cases:

SOAP web services
Configuration files (web.xml, pom.xml)
Document storage (Office files)
RSS feeds and sitemaps

📄 YAML - YAML Ain't Markup Language

YAML is a human-friendly data serialization format that is widely used for configuration files. It uses indentation to define structure, so there is no need for brackets or braces.

Key Features:

Easy to Read: One of the easiest formats for humans to understand.
Indentation-Based: Structure is defined using spaces and indentation.
No Brackets: Clean and minimal syntax.
Supports Comments: You can add comments using the # symbol.

Syntax Features:

Colon (:) for key-value pairs
Hyphen (-) for lists
Indentation (2 or 4 spaces) for nesting
Quotes optional for strings

Example:

# Employee Configuration
name: Rahul Kumar
age: 28
isStudent: false

# Skills List
skills:
  - JavaScript
  - Python
  - React

# Nested Address Object
address:
  city: Mumbai
  state: Maharashtra
  pincode: 400001

# Array of Objects
projects:
  - title: E-commerce Website
    status: completed
    year: 2023
    technologies:
      - React
      - Node.js
      - MongoDB

  - title: Mobile App
    status: in-progress
    year: 2024
    technologies:
      - React Native
      - Firebase

Common Use Cases:

Docker Compose files
Kubernetes configurations
CI/CD pipelines (GitHub Actions, GitLab CI)
Application configuration files

⚙️ TOML - Tom's Obvious Minimal Language

TOML is a configuration file format inspired by INI files. It is human-readable and designed to be easy and unambiguous to parse. TOML is very popular in Rust and Python projects.

Key Features:

Clear Meaning: The syntax is easy to understand and has no confusion.
Minimal: Simple structure that is easy to read and parse.
Type Safety: Supports clear data types.
Supports Comments: You can add comments using the # symbol.

Data Types:

String, Integer, Float, Boolean
Datetime
Arrays
Tables (objects)

Example:

# Employee Configuration File

name = "Rahul Kumar"
age = 28
isStudent = false

# Skills Array
skills = ["JavaScript", "Python", "React"]

# Address Table
[address]
city = "Mumbai"
state = "Maharashtra"
pincode = 400001

# Array of Tables - Projects
[[projects]]
title = "E-commerce Website"
status = "completed"
year = 2023
technologies = ["React", "Node.js", "MongoDB"]

[[projects]]
title = "Mobile App"
status = "in-progress"
year = 2024
technologies = ["React Native", "Firebase"]

# Nested Table Example
[database]
server = "192.168.1.1"
port = 5432
connection_max = 5000
enabled = true

[database.credentials]
username = "admin"
password = "secure_password"

Common Use Cases:

Cargo.toml (Rust package manager)
pyproject.toml (Python projects)
Application configuration files
Build system configurations

🎨 Format Function

The Format function converts data into a human-readable format. It adds proper indentation and line breaks to make the code easy to read.

Purpose:

Converts minified or unformatted data into a properly indented and readable format.

How it Works:

Adds whitespace and line breaks
Maintains proper indentation levels
Organizes nested structures in a clear and visual way

Before Format (Minified):

{"name":"Rahul","age":28,"skills":["JS","Python"],"address":{"city":"Mumbai"}}

After Format:

{
  "name": "Rahul",
  "age": 28,
  "skills": [
    "JS",
    "Python"
  ],
  "address": {
    "city": "Mumbai"
  }
}

Beautify Pretty Print Indent

📦 Minify Function

The Minify function compresses data by removing unnecessary whitespace, line breaks, and indentation. This reduces the file size and helps in faster network transfer.

Purpose:

Reduces file size to improve loading speed and minimize bandwidth usage.

How it Works:

Removes extra whitespace
Eliminates line breaks and indentation
Reduces size while keeping the data unchanged

Before Minify (Formatted):

{
  "name": "Rahul Kumar",
  "age": 28,
  "skills": [
    "JavaScript",
    "Python",
    "React"
  ]
}

After Minify:

{"name":"Rahul Kumar","age":28,"skills":["JavaScript","Python","React"]}

Benefits:

Smaller files. How much smaller depends on how deeply the data was indented; the status bar shows the exact number of bytes saved.
Faster network transfer
Less bandwidth usage
Improved load times

Compress Optimize Reduce Size

🔧 Repair Function

Repair takes JSON that won't parse and fixes the mistakes that most often come from hand-editing or from copying JavaScript code. It is available for JSON in the formatter.

What Repair fixes:

Keys without quotes, such as {name: "Rahul"}
Trailing commas after the last item in an object or array
Comments written as // … or /* … */
Brackets or braces that were never closed

What it doesn't fix:

Single quotes around keys or strings
Missing commas between properties
Python values like True, False or None

For those, the validator shows the exact line and column so you can correct them by hand.

Example

Before Repair:

{name: "Rahul", age: 28, // added later
 "skills": ["JS", "Python",],

After Repair:

{
  "name": "Rahul",
  "age": 28,
  "skills": [
    "JS",
    "Python"
  ]
}

The keys got their quotes, the comment and the trailing comma are gone, and the missing closing brace was added.

Fix Errors Auto-correct Validate

🔤 Sort JSON/XML Function

The Sort function arranges data keys in alphabetical order. This helps keep the data organized and makes it easier to compare.

Purpose:

Organizes data by sorting keys in alphabetical order.

Features:

Sorts keys alphabetically
Also sorts keys inside nested objects
Keeps the order of array items (only keys are sorted)
Makes data comparison easier
Sort XML does the same for child elements

Before Sort:

{
  "name": "Rahul",
  "city": "Mumbai",
  "age": 28,
  "email": "rahul@example.com",
  "country": "India"
}

After Sort:

{
  "age": 28,
  "city": "Mumbai",
  "country": "India",
  "email": "rahul@example.com",
  "name": "Rahul"
}

Use Cases:

Comparing two JSON files
Version control (consistent ordering)
Generating checksums
Data organization

Alphabetical Organize Compare

🔄 Format Conversion Functions

Conversions take the content of the editor and show the result in the right-hand panel. Your original stays unchanged on the left. The examples below show the exact output of each conversion.

1. JSON to XML

Each key becomes an element and each value becomes the element's text. Arrays turn into the same element repeated once per item, because XML has no separate list syntax. The whole document is wrapped in a <root> element, since XML needs exactly one root, and an XML declaration is added at the top.

JSON input:

{
  "employee": {
    "name": "Rahul",
    "age": 28,
    "skills": ["JavaScript", "Python"]
  }
}

XML output:

<?xml version='1.0' encoding='UTF-8'?>
<root>
  <employee>
    <name>Rahul</name>
    <age>28</age>
    <skills>JavaScript</skills>
    <skills>Python</skills>
  </employee>
</root>

2. XML to JSON

Child elements become keys and repeated elements become arrays. The root element itself becomes the outer object, so its name does not appear in the output. All values are strings, because XML text has no types.

XML input:

<person>
  <name>Rahul</name>
  <age>28</age>
</person>

JSON output:

{
  "name": "Rahul",
  "age": "28"
}

3. JSON to YAML

Objects become indented blocks and arrays become lists with a dash per item. Quotes are only added where YAML needs them. For example, text that looks like a number or a yes/no value keeps its quotes, so it stays text.

JSON input:

{"name": "Rahul", "age": 28, "skills": ["JS", "Python"]}

YAML output:

name: Rahul
age: 28
skills:
- JS
- Python

4. JSON to TOML

Top-level values become key = value lines, nested objects become [tables], and arrays of objects become repeated [[tables]]. TOML has no null, so keys with a null value are left out.

JSON input:

{
  "database": {
    "server": "localhost",
    "port": 5432
  }
}

TOML output:

[database]
server = "localhost"
port = 5432

5. XML to YAML

Works like XML to JSON: repeated elements become a list and the root element becomes the top level.

XML input:

<user>
  <name>Keshav</name>
  <skills>Java</skills>
  <skills>Spring</skills>
</user>

YAML output:

name: Keshav
skills:
- Java
- Spring

6. XML to TOML

Useful when moving settings from an older XML config to a TOML file. Nested elements become tables. Values come out as strings, again because XML text has no types, so change "5432" to 5432 by hand where a number is expected.

XML input:

<config>
  <database>
    <server>localhost</server>
    <port>5432</port>
  </database>
</config>

TOML output:

[database]
server = "localhost"
port = "5432"

Other conversions

CSV to JSON, XML or SQL: the first row becomes the field names.
JSON or XML to CSV: nested objects are flattened into columns like address.city.
Properties to YAML and back: for Spring Boot configuration files.

Transform Convert Migrate Interchange

💡 Pro Tips & Best Practices

JSON Best Practices:

Always use double quotes for strings
No trailing commas allowed
Use consistent indentation (2 or 4 spaces)
Validate before you commit or send, for example with the JSON formatter

XML Best Practices:

Use meaningful tag names
Close all tags properly
Use attributes for metadata only
Include XML declaration at top

YAML Best Practices:

Use 2 spaces for indentation (not tabs)
Quote strings with special characters
Use comments to explain complex sections
Keep nesting levels reasonable

TOML Best Practices:

Group related configuration together
Use tables for nested data
Prefer arrays of tables for repeated data
Add comments for important settings

Learn the data formats

On this page

{ } JSON - JavaScript Object Notation

Key Features of JSON:

Data Types:

Example:

Common Use Cases:

</> XML - Extensible Markup Language

Key Features:

Syntax Rules:

Example:

Common Use Cases:

📄 YAML - YAML Ain't Markup Language

Key Features:

Syntax Features:

Example:

Common Use Cases:

⚙️ TOML - Tom's Obvious Minimal Language

Key Features:

Data Types:

Example:

Common Use Cases:

🎨 Format Function

Purpose:

How it Works:

Before Format (Minified):

After Format:

📦 Minify Function

Purpose:

How it Works:

Before Minify (Formatted):

After Minify:

Benefits:

🔧 Repair Function

What Repair fixes:

What it doesn't fix:

Example

Before Repair:

After Repair:

🔤 Sort JSON/XML Function

Purpose:

Features:

Before Sort:

After Sort:

Use Cases:

🔄 Format Conversion Functions

1. JSON to XML

2. XML to JSON

3. JSON to YAML

4. JSON to TOML

5. XML to YAML

6. XML to TOML

Other conversions

💡 Pro Tips & Best Practices

JSON Best Practices:

XML Best Practices:

YAML Best Practices:

TOML Best Practices: