Is this JSON to YAML converter free?

Yes, our JSON to YAML converter is completely free with no usage limits. There's no signup required, and your data is processed entirely in your browser without being sent to any server.

Can I convert YAML back to JSON?

Yes! Use our YAML to JSON converter at /yaml-to-json for reverse conversion. Both tools work instantly in your browser.

Does the converter preserve data types?

Yes, our converter accurately preserves all JSON data types including strings, numbers, booleans, null values, nested objects, and arrays in the YAML output.

Can I use this for OpenAPI/Swagger files?

Absolutely. Our converter handles OpenAPI 3.0 and Swagger 2.0 specification files, properly converting the entire API definition structure to YAML format.

Is my data secure when using this converter?

Yes. All conversion happens locally in your browser using JavaScript. Your JSON data is never sent to any server or stored anywhere. Your data remains completely private.

What if my JSON has errors?

The converter validates your JSON before conversion. You'll see a clear error message identifying the problem, such as missing commas, unmatched brackets, or invalid characters.

Can I convert large JSON files?

Yes. The converter runs in your browser and can handle files as large as your browser's memory allows. For extremely large files, consider using command-line tools like yq or jq.

Does the output preserve key order?

Yes. The converter maintains the same key order from your original JSON. Keys appear in the YAML output in the same sequence you provided them.

What indentation does the YAML output use?

The default output uses 2-space indentation, which is the most common YAML style. You can change this to 4 spaces if your project requires it.

JSON vs YAML: Differences, When to Use Each, and Conversion Guide

Quick Comparison

Here's a side-by-side comparison of the same data in both formats:

JSON Example

json

{
  "application": {
    "name": "web-service",
    "version": "2.0.0",
    "port": 8080
  },
  "database": {
    "host": "localhost",
    "port": 5432,
    "ssl": true
  },
  "features": ["auth", "logging", "cache"]
}

YAML Example

yaml

# Application configuration
application:
  name: web-service
  version: "2.0.0"
  port: 8080

# Database settings
database:
  host: localhost
  port: 5432
  ssl: true

# Enabled features
features:
  - auth
  - logging
  - cache

The YAML version includes comments, uses less punctuation, and displays the same structure through indentation rather than braces.

What Is JSON

JSON (JavaScript Object Notation) is a lightweight data interchange format. Douglas Crockford popularized JSON in the early 2000s as a simpler alternative to XML for transmitting structured data between web servers and browsers.

JSON Characteristics

Strict Syntax — Every key must be quoted. Commas separate elements. Braces and brackets define structure.
Data Types — Strings, numbers, booleans, null, arrays, and objects.
No Comments — The specification does not allow comments.
Language Independent — Parsers exist for virtually every programming language.
Native JavaScript — JavaScript can parse JSON without external libraries.

What Is YAML

YAML (YAML Ain't Markup Language) is a human-friendly data serialization format. Originally designed for configuration files and data exchange, YAML emphasizes readability over strict parsing rules.

YAML Characteristics

Indentation-Based — Structure defined by whitespace, not punctuation.
Comments Supported — Use # for inline and block comments.
Flexible Quoting — Quotes optional for most strings.
Rich Data Types — Supports dates, timestamps, and custom types.
Multi-Document — Single file can contain multiple documents.

Key Differences

Syntax and Structure

Aspect	JSON	YAML
Structure	Braces and brackets []	Indentation
Keys	Must be quoted	Quotes optional
Strings	Must be quoted	Quotes optional
Comments	Not supported	# for comments
Multi-line	Escape characters	Block scalars
File size	Generally larger	Generally smaller

Data Types

Type	JSON	YAML
String	"text"	text or "text"
Number	42, 3.14	42, 3.14
Boolean	true, false	true, false, yes, no, on, off
Null	null	null, ~, empty
Date	"2026-01-15" (string)	2026-01-15 (native)
Binary	Not supported	Base64 with !!binary

Comments

This is often the deciding factor between formats.

JSON: No Comments

No comment support whatsoever. Any attempt to add comments creates invalid JSON.

YAML: Full Support

yaml

# This is a block comment
key: value  # Inline comment

Readability

YAML is more readable for humans:

+No visual clutter from braces and quotes
+Natural language feel for configuration
+Comments document the "why" behind values
+Whitespace creates visual structure

JSON is more readable for machines:

+Strict format eliminates ambiguity
+Faster to parse (less interpretation)
+No indentation-sensitive parsing required
+Clear delimiters for data boundaries

When to Use JSON

API Communication

REST APIs universally accept JSON. HTTP request and response bodies typically use JSON format. JavaScript applications parse JSON natively without external dependencies.

Data Storage

NoSQL databases like MongoDB store documents in JSON-like formats. JSON's strict structure prevents ambiguity in stored data. Query languages often expect JSON input.

Configuration for JavaScript

Node.js package.json, tsconfig.json, and similar configuration files use JSON because JavaScript tooling parses JSON natively.

Cross-Language Data Exchange

When transmitting data between different programming languages, JSON's strict format ensures consistent parsing. Every language has reliable JSON libraries.

Machine-Generated Data

When applications generate configuration or data files programmatically, JSON's strict format is easier to produce correctly than YAML's whitespace-sensitive format.

When to Use YAML

DevOps Configuration

Kubernetes, Docker Compose, Ansible, GitHub Actions, and most DevOps tools use YAML as their primary configuration format. YAML's readability helps teams review and understand complex configurations.

Human-Edited Files

When humans regularly read and modify configuration files, YAML reduces errors. No matching braces, no remembering commas, no escape sequences for multi-line content.

Documentation in Configuration

YAML's comment support allows documentation alongside configuration values:

yaml

# Maximum connections to database pool
# Increase for high-traffic periods
database_pool_size: 20

# Cache TTL in seconds
# Set to 0 to disable caching
cache_ttl: 3600

Complex Nested Structures

Deeply nested objects are easier to understand in YAML. The visual indentation shows hierarchy clearly without counting braces or relying on code folding.

Infrastructure as Code

CloudFormation, Terraform (HCL also available), Helm charts, and other IaC tools commonly use YAML. Teams can review infrastructure changes in pull requests more easily with YAML.

Conversion Between Formats

JSON and YAML represent equivalent data structures. Any valid JSON converts to valid YAML and vice versa (with some YAML features that don't exist in JSON).

Online Conversion Tools

JSON to YAML Converter

Instant conversion in your browser

YAML to JSON Converter

Reverse conversion tool

Command Line Tools

bash

# Using yq
yq -o=yaml file.json > file.yaml
yq -o=json file.yaml > file.json

# Using Python
python -c "import json, yaml, sys; yaml.dump(json.load(sys.stdin), sys.stdout)" < file.json

Frequently Asked Questions

What is the difference between JSON and YAML?

JSON uses braces and brackets [] with mandatory quotation marks to define structure. YAML uses indentation and whitespace instead. JSON is stricter and better for machine processing. YAML is more readable and supports comments, making it better for human-edited configuration files.

Is YAML better than JSON?

Neither format is universally better. YAML is better for configuration files that humans edit because of readability and comment support. JSON is better for data interchange between applications because of strict parsing and universal support.

Can JSON and YAML represent the same data?

Yes. Any valid JSON is also valid YAML (JSON is a subset of YAML). You can convert between formats without losing data structure. However, YAML-specific features like comments and anchors don't exist in JSON.

Why do DevOps tools use YAML?

DevOps configuration files are frequently read and modified by humans. YAML's clean syntax, comment support, and visual hierarchy make reviewing and editing these files easier. Kubernetes standardized on YAML, influencing the broader ecosystem.

Is JSON faster to parse than YAML?

Generally yes. JSON's strict format allows faster parsing because there's less interpretation needed. YAML parsers must handle indentation, multiple boolean formats, implicit typing, and other flexible features. For most applications, the difference is negligible.

Can YAML have comments?

Yes. YAML supports comments using the # symbol. Comments can appear on their own line or after a value on the same line. JSON does not support comments at all.

Is JSON valid YAML?

Yes. JSON is technically a subset of YAML. Any valid JSON document is also a valid YAML document. YAML parsers can read JSON files directly.

Which format should I use for API responses?

JSON. REST APIs universally use JSON for request and response bodies. Every HTTP client library supports JSON natively. Using YAML for API responses would require clients to include YAML parsing libraries.

Which format should I use for Kubernetes?

YAML. While Kubernetes accepts both formats, the community overwhelmingly uses YAML. Documentation, examples, and tooling assume YAML. Use YAML unless you have specific reasons to use JSON.

Summary: JSON vs YAML Decision Guide

JUse JSON When:

Building APIs and web services
Storing data in databases
Exchanging data between systems
Working with JavaScript applications
Generating configuration programmatically

YUse YAML When:

Writing configuration files for DevOps tools
Creating Kubernetes manifests
Defining CI/CD pipelines
Writing Ansible playbooks
Any file humans will read and edit regularly

Convert Between Formats

Convert between formats with our free tools:

JSON vs YAML: Complete Comparison Guide

Quick Comparison

What Is JSON

JSON Characteristics

What Is YAML

YAML Characteristics

Key Differences

Syntax and Structure

Data Types

Comments

JSON: No Comments

YAML: Full Support

Readability

YAML is more readable for humans:

JSON is more readable for machines:

When to Use JSON

API Communication

Data Storage

Configuration for JavaScript

Cross-Language Data Exchange

Machine-Generated Data

When to Use YAML

DevOps Configuration

Human-Edited Files

Documentation in Configuration

Complex Nested Structures

Infrastructure as Code

Conversion Between Formats

Online Conversion Tools

JSON to YAML Converter

YAML to JSON Converter

Command Line Tools

Frequently Asked Questions

Summary: JSON vs YAML Decision Guide

JUse JSON When:

YUse YAML When:

Convert Between Formats

JSON to YAML Converter

YAML to JSON Converter

Python Guide