Validate and Fix Your JSON Instantly with AI

Use our free online JSON Validator to check and fix JSON syntax errors. Instantly detect error line numbers, spot duplicate keys, enforce schema validation, and auto-correct issues with AI-powered fixing. So easy to use, you can fix JSON mistakes in seconds—perfect for developers, testers, and data engineers working with APIs, configurations, and data migration.

Your adventure is about to begin

How to Use the JSON Validator with AI Fix

Basic Validation Steps

1.
Input JSON: Paste your JSON data into the text area or upload a .json file using the Upload button.
2.
Validate: Click the "Validate JSON" button to check for syntax errors and structural issues.
3.
Review Results: Check the validation results panel for errors, warnings, and performance metrics.
4.
Export Report: Download detailed validation reports for documentation or debugging.

AI-Powered Fix Feature

1.
Detect Errors: When validation fails, the "Fix with AI" button appears automatically.
2.
AI Analysis: Click "Fix with AI" to let our intelligent system analyze error patterns and line numbers.
3.
Auto-Correction: The AI applies fixes like quote conversion, comma removal, and property name formatting.
4.
Re-validation: The corrected JSON is automatically re-validated to ensure it's now valid.

Multiple Input Methods

Paste JSON directly, upload files, or load sample data for testing

AI-Powered Fixing

Intelligent error detection and automatic correction of common JSON issues

Advanced Options

Real-time validation, schema checking, and customizable validation rules

AI Fix Feature - Technical Details

What the AI Can Fix

Fix
Single quotes → Double quotes conversion
Fix
Trailing comma removal in objects/arrays
Fix
Unquoted property names → Quoted names
Fix
Boolean/null value corrections (true/false/null)
Fix
Comment removal (// and /* */ style)
Fix
String value detection and proper quoting

How It Works

1. Error Analysis: The AI analyzes specific error messages and line numbers from the JSON parser.

2. Pattern Recognition: Identifies common JSON syntax patterns and applies appropriate fixes.

3. Context-Aware Fixing: Uses surrounding code context to make intelligent corrections.

4. Validation Loop: Re-validates the fixed JSON to ensure correctness.

Pro Tips for Best Results

The AI works best with common syntax errors - complex structural issues may require manual fixing
Always review the AI-fixed JSON before using it in production environments
Use the real-time validation feature to catch errors as you type
Upload large JSON files instead of pasting to avoid browser limitations
Enable strict mode for more comprehensive validation checks

Advanced JSON Validation Features

Validation Features

Real-time validation as you type
JSON Schema validation support
Performance metrics and scoring
Detailed error analysis with suggestions
Structure analysis (depth, complexity)
Duplicate key detection
File size and complexity warnings
Line-by-line error reporting

Advanced Options

Strict mode validation
Custom validation rules
Validation history tracking
Export detailed validation reports
Batch file validation
Performance optimization tips
JSON best practices checking
AI-powered error fixing

JSON Validation Tips

JSON property names must be in double quotes
String values must be in double quotes
Numbers should not have leading zeros
Boolean values are written as true or false
Arrays are enclosed in square brackets []
Objects are enclosed in curly braces {}
The last element in an array or object should not have a trailing comma
Use the AI fix feature for automatic error correction

Common Use Cases for JSON Validation

API Development

Validate API request/response payloads before deployment to ensure proper data exchange.

Configuration Files

Check JSON configuration files for applications, ensuring no syntax errors break functionality.

Data Migration

Validate JSON data before importing into databases or transferring between systems.

Testing & QA

Ensure test data and mock responses are properly formatted for automated testing.

Schema Validation

Validate JSON against specific schemas to ensure data structure compliance.

Learning & Education

Perfect for students learning JSON syntax with AI-powered error correction and explanations.

Frequently Asked Questions

How to Validate JSON Data Online for Free?

Validate JSON data effortlessly with our free online JSON validator tool. Paste your JSON into the input field or upload a .json file, then click 'Validate JSON.' The tool instantly checks for syntax errors and displays any issues with clear error messages. Perfect for developers ensuring API data integrity, this JSON checker works in your browser, offering fast, secure validation without server-side processing. Use our online JSON validator to debug JSON and ensure error-free data for your applications.

What Are Common JSON Validation Errors to Watch For?

Common JSON validation errors include missing or extra commas, unquoted property names, single quotes instead of double quotes, trailing commas in arrays or objects, and invalid escape sequences in strings. Our free JSON validator tool detects these issues instantly, providing detailed error messages to help developers fix them. Paste or upload your JSON to our online JSON checker for quick analysis. This tool ensures your JSON data is syntactically correct, preventing errors in APIs or applications.

How Does the AI-Powered JSON Fix Feature Work?

Our AI-powered JSON fix feature automatically detects and corrects common JSON syntax errors. When validation fails, click the 'Fix with AI' button to let our intelligent system analyze the errors and apply corrections like converting single quotes to double quotes, removing trailing commas, and fixing unquoted property names. The AI understands JSON structure and applies fixes based on the specific error types and line numbers detected during validation.

Why Is JSON Validation Important for Developers?

JSON validation ensures your data adheres to correct JSON syntax, enabling proper parsing by applications. Invalid JSON can cause crashes, API failures, or unexpected behavior in web and mobile apps. Our free JSON validator tool helps developers verify JSON integrity, catching errors like missing commas or incorrect quotes. Use this online JSON checker to validate data for APIs or data processing, ensuring reliability and performance. Paste or upload your JSON to get instant feedback, all in your browser without software installation.

Can I Validate a JSON File Online with a Free Tool?

Yes, our free JSON validator tool allows you to validate JSON files easily. Click the 'Upload' button to upload a .json file, and the tool will read and check its syntax for errors, displaying any issues instantly. Ideal for developers working with API responses or large datasets, this online JSON checker ensures error-free JSON without server-side processing. Paste or upload your JSON data to validate it quickly, ensuring compatibility and reliability for your applications.

What Makes JSON Data Valid for Validation Tools?

Valid JSON follows strict syntax rules: property names and string values must use double quotes, numbers cannot have leading zeros, arrays use square brackets, objects use curly braces, and trailing commas are not allowed. Our free JSON validator tool checks these rules, ensuring your JSON is parsable by applications. Paste or upload your JSON to our online JSON checker for instant validation and error reporting. This tool helps developers ensure API data or configurations are error-free, enhancing application reliability.

Ready to Get Started?

Choose from our suite of JSON tools to start processing your data right away.

JSON Formatter

Beautify and format JSON with syntax highlighting and customizable indentation.

Batch JSON Processor

Process multiple JSON files simultaneously - format, minify, or validate in bulk.

AI JSON Generator

Generate valid JSON from plain English using AI technology.

JSON Editor

Edit JSON with tree view, real-time validation, and statistics.

JSON Compare

Compare two JSON files with visual diff highlighting and detailed analysis.

JSON Schema Generator

Generate JSON Schema validation rules from JSON objects.

- For a complete overview, see our full GuideJSON Validation

- For a complete overview, see our full GuideMastering JSON Validation: Tools, Techniques & Tips