Online JSON Formatter & Validator Tool

This free online JSON formatter and validator helps developers instantly beautify, clean and check JSON data. It supports real-time error detection, syntax highlighting, minification, tree view visualization, and large file handling. Use this tool to debug API responses, fix malformed JSON, work with JavaScript or backend services, and quickly format JSON for development. No installation or login required — everything runs securely in your browser.

Saved JSONs

No saved JSONs yet.

Shared JSONs

No shared JSONs yet.

How to Format and Validate JSON Online

JSON Toolaska is your go-to free online JSON formatter and validator. Perfect for developers working with APIs, debugging JSON responses, or cleaning up data structures. Our tool makes JSON formatting and validation quick and easy:

Paste Your JSON: Copy your JSON data and paste it into the editor
Auto-Format: Watch as your JSON is instantly beautified with proper indentation
Validate Syntax: Get real-time error detection and syntax validation
View Structure: Use the tree view to explore nested JSON data
Share or Export: Copy the formatted JSON or share it with colleagues

Built for developers, by developers. Our JSON formatter supports keyboard shortcuts, handles large files efficiently, and works offline. No registration required - just paste your JSON and start formatting.

How do I format my JSON data?

Simply paste your JSON data into the editor above. The formatter will automatically detect your input and format it with proper indentation. You can also use the tree view to explore nested structures and the validation feature will automatically check for any syntax errors or structural issues in your JSON.

What is JSON Schema validation and how does it work?

JSON Schema validation is a powerful feature that allows you to define and validate the structure of your JSON data. It helps ensure that your JSON follows specific rules, data types, and formats. Our validator checks your JSON against predefined schemas to verify properties, required fields, data types, and nested object structures.

How can I use the Tree View feature?

The Tree View feature provides an interactive way to explore your JSON data. Click on the Tree View mode to transform your JSON into a collapsible tree structure. You can expand/collapse nested objects and arrays, making it easier to navigate through complex JSON structures. This is particularly useful when working with large JSON files.

What common JSON syntax errors does the validator detect?

Our validator catches several common JSON syntax errors including: missing or extra commas between properties, unclosed brackets or braces, invalid property names (missing quotes), incorrect value types, malformed arrays, and invalid escape sequences in strings. The tool highlights these errors in real-time as you type or paste your JSON data.

Can I minify my JSON data?

Yes! While our tool primarily focuses on formatting and beautifying JSON with proper indentation, you can also minify your JSON data to remove all unnecessary whitespace. This is useful when you need to reduce the file size for transmission or storage. Simply use the compact mode in the editor to remove all extra spaces and line breaks while maintaining valid JSON syntax.

Online JSON Formatter & Validator Tool

Saved JSONs

Shared JSONs

How to Format and Validate JSON Online

Free JSON Beautifier & Validator Tool

Smart Formatting

Validation

JSON Validator

Tree View

Quick Copy

Online JSON Validator & Syntax Checker

What is JSON?

Why is JSON So Widely Used?

Lightweight and Fast

Human-Readable Format

Perfect for APIs

Language Agnostic

Used in Configurations

Where is JSON Used?

Common Mistakes in JSON

Why Quick JSON?

JSON Tips and Best Practices for Beginners

Always Use Double Quotes

Validate Before You Use

Keep It Simple and Clear

Use Meaningful Keys

Minify for Speed, Beautify for Clarity

Frequently Asked Questions

How do I format my JSON data?

How do I format my JSON data?

What is JSON Schema validation and how does it work?

What is JSON Schema validation and how does it work?

How can I use the Tree View feature?

How can I use the Tree View feature?

What common JSON syntax errors does the validator detect?

What common JSON syntax errors does the validator detect?

Can I minify my JSON data?

Can I minify my JSON data?

Our Tools

Quick Compiler

Quick Differ

Quick JSON

JSON Formatter

Quick Compiler

Quick Differ