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.
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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
What the AI Can Fix
- FixSingle quotes → Double quotes conversion
- FixTrailing comma removal in objects/arrays
- FixUnquoted property names → Quoted names
- FixBoolean/null value corrections (true/false/null)
- FixComment removal (// and /* */ style)
- FixString value detection and proper quoting
How It Works
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
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
trueorfalse - 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
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.
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