JSON Validator & Auto-Fix Tool

Automatically detect and fix JSON syntax errors with our intelligent JSON validator and repair tool

JSON Input

Paste your broken JSON data here to automatically fix

Click anywhere or press any key to enable all 0 editors with syntax highlighting

Fixed JSON Outputs

No fixed outputs yet. Click "Auto-Fix JSON" to automatically repair your JSON.

Ready to Fix Your JSON Files?

Join thousands of developers who trust our OJF for their daily workflow. Fast, reliable, and completely free.

100% Free
No Registration
Privacy Protected

JSON Validator & Auto-Fix Tool - Detect & Repair JSON Syntax Errors Automatically

Advanced JSON validator and auto-repair tool that detects syntax errors, missing commas, bracket mismatches, and invalid formatting. Automatically fix common JSON issues and validate against JSON Schema with detailed error reporting.

Key Features of OJF

Everything you need to manage your data

Advanced JSON Validation Features

  • Real-time syntax error detection with precise line numbers
  • Comprehensive JSON Schema validation support
  • Missing comma and bracket detection with auto-fix suggestions
  • Invalid string quotation and escaping error identification
  • Data type validation and format checking
  • Duplicate key detection and resolution
  • Value validation against expected data types
  • Structural integrity analysis for complex nested JSON

Intelligent Auto-Fix Capabilities

  • Automatic comma insertion for missing separators
  • Smart bracket and brace matching with auto-completion
  • Quote correction for unescaped strings and keys
  • Trailing comma removal for JSON compliance
  • Invalid character detection and replacement
  • Boolean and null value correction
  • Number format validation and standardization
  • Unicode escape sequence handling and conversion

Professional Validation Tools

  • JSON Schema compliance checking with detailed reports
  • Custom validation rules for business logic verification
  • API response validation for endpoint testing
  • Configuration file validation for deployment safety
  • Data migration validation for database imports
  • Multi-format validation (JSON, JSON5, JSONC support)
  • Large file validation up to 15MB with performance optimization
  • Batch validation for multiple JSON files simultaneously

Error Analysis & Reporting

  • Detailed error reports with context and suggestions
  • Visual error highlighting with color-coded indicators
  • Error severity classification (critical, warning, info)
  • Fix confidence scoring for auto-repair suggestions
  • Validation history tracking for quality assurance
  • Export validation reports for documentation and auditing
  • Integration APIs for automated validation workflows
  • Team collaboration features for error resolution

Complete JSON Validation & Fixing Guide

1

Paste your potentially invalid JSON into the validator or upload a JSON file

2

Review the automatic error detection with highlighted syntax issues

3

Examine detailed error messages showing exact line and column locations

4

Use the 'Auto-Fix' feature to automatically repair common JSON errors

5

Review suggested fixes and accept or modify them based on your needs

6

Validate the corrected JSON against JSON Schema if you have specific requirements

7

Test the fixed JSON in your application to ensure it works as expected

8

Download the corrected JSON or copy it for use in your projects

9

Save validation reports for documentation and quality assurance purposes

Why Choose Us?

Feature
Online JSON Formatt(OJF)
Other Tools
Auto-fix capabilitiesIntelligent repairManual fixing only
Error precisionLine & column accuracyGeneral error messages
Schema validationFull JSON Schema supportSyntax validation only
Fix confidence scoringReliability indicatorsNo confidence metrics
Batch validationMultiple filesSingle file only
Large file supportUp to 15MB1-2MB limit
Validation reportsExportable reportsNo reporting
Fix suggestionsContext-aware suggestionsBasic error detection
JSON variantsJSON, JSON5, JSONCJSON only
API integrationAutomation readyManual use only

Frequently Asked Questions