YAML to JSON Converter

YAML to JSON & JSON to YAML Converter - Free Online Bidirectional Tool

This free YAML to JSON converter instantly transforms data between YAML and JSON formats in both directions - paste YAML and get clean JSON, or paste JSON and get readable YAML. Both formats are used to store structured data and configuration, but they serve different purposes: JSON is the standard for APIs and data exchange because it is compact and universally parseable, while YAML is favored for configuration files (Docker Compose, Kubernetes, GitHub Actions, CI/CD pipelines) because it is human-readable and supports comments. Converting between them is a daily task for developers, DevOps engineers, and anyone working with modern infrastructure tooling.

Use this online converter to switch between the two formats without installing anything or writing code. The tool handles nested objects, arrays, multi-line strings, and all standard data types, preserving your data structure exactly during the conversion. Simply toggle the direction - YAML to JSON or JSON to YAML - paste your input, and copy the converted output instantly. Whether you need to convert a Kubernetes manifest to JSON for an API call, turn a JSON API response into a readable YAML config, or just validate that your data parses correctly in both formats, this converter does it in your browser with no sign-up and no data sent to a server.

How to Use the YAML ⇄ JSON Converter

1. Step 1 - Choose Your Conversion Direction

   Select whether you want to convert YAML to JSON or JSON to YAML using the direction toggle at the top of the tool. YAML to JSON is the most common direction - developers convert human-readable config files into the compact JSON format that APIs and programs expect. JSON to YAML is equally useful when you receive a JSON API response or data file and want to make it more readable, add comments, or use it as a configuration file. The tool defaults to YAML to JSON, but you can switch directions at any time and the conversion updates instantly.

2. Step 2 - Paste Your Input Data

   Paste your source data into the input panel on the left. For YAML to JSON, paste your YAML - indentation-based structure with key-value pairs, lists, and nested mappings. For JSON to YAML, paste valid JSON with its curly braces and square brackets. The tool accepts data of any size, from a single key-value pair to large multi-hundred-line configuration files. You can also type or edit directly in the input panel. If your input has syntax errors, the converter highlights the problem so you can fix it before converting.

3. Step 3 - Review the Converted Output

   The converted result appears instantly in the output panel on the right. When converting YAML to JSON, the output is properly formatted (pretty-printed) JSON with correct indentation, quoted keys, and bracketed arrays. When converting JSON to YAML, the output uses clean indentation-based YAML syntax with unquoted keys where valid. The conversion preserves your exact data structure - every nested object, array element, and value type is maintained accurately. Review the output to confirm the structure matches your expectation, especially for deeply nested data.

4. Step 4 - Copy or Download the Result

   Click the copy button to copy the converted output to your clipboard, ready to paste into your code editor, configuration file, API client, or terminal. For larger conversions, use the download option to save the output directly as a .json or .yaml file. The converted data is exactly what your target system expects - valid JSON for programmatic use, or valid YAML for configuration files. Because the conversion happens entirely in your browser, your data never leaves your device, making it safe for sensitive configuration files containing internal hostnames, environment variables, or infrastructure details.

YAML to JSON Conversion Examples

Example 1 - Simple Key-Value Configuration

A basic application config showing how YAML key-value pairs map to JSON. This is the most common conversion pattern.

name: my-application
version: 1.4.2
port: 8080
debug: true

{
  "name": "my-application",
  "version": "1.4.2",
  "port": 8080,
  "debug": true
}

Note how YAML's unquoted strings become quoted in JSON, while numbers (8080) and booleans (true) remain unquoted in both formats because they are typed values, not strings. The version "1.4.2" stays a string because it contains characters that are not purely numeric.

Example 2 - Nested Objects and Arrays

A more realistic configuration with nested structure and a list, similar to what you would find in a service config file.

server:
  host: localhost
  port: 5432
  credentials:
    username: admin
    password: secret123
features:
  - authentication
  - logging
  - caching

{
  "server": {
    "host": "localhost",
    "port": 5432,
    "credentials": {
      "username": "admin",
      "password": "secret123"
    }
  },
  "features": [
    "authentication",
    "logging",
    "caching"
  ]
}

YAML's indentation-based nesting becomes JSON's curly braces, and YAML's dash-prefixed list items become a JSON array with square brackets. The data hierarchy is preserved exactly.

Example 3 - JSON to YAML (Reverse Direction)

Converting a JSON API response into readable YAML - useful when you want to turn data into a config file or make it easier to read and comment.

{
  "user": {
    "id": 1042,
    "name": "Jane Doe",
    "roles": ["editor", "reviewer"],
    "active": true,
    "metadata": null
  }
}

user:
  id: 1042
  name: Jane Doe
  roles:
    - editor
    - reviewer
  active: true
  metadata: null

The JSON converts to clean, readable YAML. Notice that YAML drops the quotation marks around strings where they are not needed, uses indentation instead of braces, and represents the array as a dash-prefixed list. The result is significantly more readable - which is exactly why developers convert JSON to YAML for configuration purposes.

Example 4 - Real-World Kubernetes Manifest Snippet

A practical DevOps example - part of a Kubernetes deployment manifest in YAML converted to JSON for programmatic processing.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-app
  labels:
    app: web
spec:
  replicas: 3

{
  "apiVersion": "apps/v1",
  "kind": "Deployment",
  "metadata": {
    "name": "web-app",
    "labels": {
      "app": "web"
    }
  },
  "spec": {
    "replicas": 3
  }
}

Kubernetes accepts both YAML and JSON, but many tools, APIs, and automation scripts work more easily with JSON. Converting manifests between the two formats is one of the most frequent reasons developers reach for a YAML to JSON converter.

How YAML to JSON Conversion Works

YAML and JSON are both data serialization formats that represent the same underlying data structures - objects (key-value mappings), arrays (ordered lists), and scalar values (strings, numbers, booleans, null). In fact, JSON is technically a subset of YAML, which means every valid JSON document is also valid YAML. This shared data model is what makes lossless conversion between them possible.

The Data Type Mapping

The converter parses your input into an in-memory data structure, then serializes that structure into the target format. The core type mappings are:

Key Structural Differences

The two formats differ in syntax even though they share a data model. JSON uses explicit delimiters - curly braces for objects, square brackets for arrays, commas between items, and mandatory double quotes around all keys and string values. YAML uses indentation (whitespace) to denote structure, dashes for list items, and allows unquoted strings, making it more compact and readable. When converting YAML to JSON, the tool adds the explicit delimiters and quotes. When converting JSON to YAML, it removes them and applies indentation.

What YAML Features Don't Survive the Round Trip

Because JSON is a subset of YAML, some YAML-specific features have no JSON equivalent and are lost when converting YAML to JSON. These include: comments (lines starting with #), anchors and aliases (the & and * references used to reuse data), multiple documents in one file (separated by ---), and custom tags. When you convert YAML to JSON and back to YAML, comments and anchors will be gone because JSON cannot represent them. The actual data values are always preserved perfectly - only these YAML-only conveniences are dropped.

Who Uses a YAML ⇄ JSON Converter?

• DevOps and platform engineers - Professionals working with Kubernetes manifests, Docker Compose files, Helm charts, and CI/CD pipeline definitions who need to convert YAML configs to JSON for API submission, or convert JSON output from tools like kubectl into readable YAML for documentation and version control.
• Backend developers integrating APIs - Developers who receive JSON responses from REST APIs and want to convert them to YAML for use in configuration files, or who maintain YAML config and need to send it to a JSON-only endpoint, using the converter to bridge the format gap without writing parsing code.
• Engineers writing GitHub Actions or GitLab CI workflows - Developers building CI/CD workflows defined in YAML who need to validate the underlying data structure by converting to JSON, or who want to programmatically generate workflow files from JSON templates.
• Technical writers and documentation teams - Writers documenting APIs or configuration options who convert JSON examples to the more readable YAML format (or vice versa) to show both formats in documentation, making examples accessible to users who prefer either syntax.
• Data engineers and analysts - Professionals working with configuration-driven data pipelines who convert between formats when integrating tools that expect different inputs, or when migrating configuration from a YAML-based system to a JSON-based one.

Common Mistakes When Converting Between YAML and JSON

YAML vs JSON - Feature Comparison

Understanding the differences between YAML and JSON helps you decide which format to use and why you might convert between them. The table below compares the two formats across the features that matter most in real-world development.

The bottom line: choose YAML when humans will read and edit the file frequently (configuration), and choose JSON when machines will exchange the data (APIs). Since different tools in a modern stack expect different formats, converting between them is a routine task - which is exactly what this bidirectional converter is built for.