Validate JSON Syntax Checker: Find Errors Fast
Invalid JSON can break your entire application. Whether you're debugging API responses or validating configuration files, a JSON validator helps you catch errors instantly. Learn how to validate JSON syntax and fix common errors quickly.
Why Validate JSON?
- 🐛Catch errors early - Find syntax errors before deployment
- ⚡Save debugging time - Pinpoint exact error locations with line numbers
- ✅Ensure compatibility - Valid JSON works across all platforms and languages
- 🔒Prevent crashes - Invalid JSON can crash parsers and applications
How to Validate JSON Online
Step 1: Paste Your JSON
Copy your JSON from API responses, config files, or code and paste it into an online JSON validator.
Step 2: Instant Validation
The validator automatically checks syntax and highlights any errors with specific line numbers and descriptions.
Step 3: Fix Errors
Use the error messages to locate and fix issues. The validator re-checks in real-time as you edit.
Most Common JSON Syntax Errors
1. Trailing Commas
Extra commas at the end of objects or arrays are invalid.
❌ Invalid:
{"name": "John", "age": 30,}✅ Fixed:
{"name": "John", "age": 30}2. Single Quotes
JSON requires double quotes. Single quotes are not allowed.
❌ Invalid:
{'name': 'John'}✅ Fixed:
{"name": "John"}3. Unquoted Keys
All object keys must be wrapped in double quotes.
❌ Invalid:
{name: "John"}✅ Fixed:
{"name": "John"}4. Missing Commas
Items must be separated by commas.
❌ Invalid:
{"name": "John" "age": 30}✅ Fixed:
{"name": "John", "age": 30}5. Unescaped Strings
Special characters in strings must be escaped.
❌ Invalid:
{"message": "She said "hello""}✅ Fixed:
{"message": "She said \"hello\""}What a Good JSON Validator Shows
- ✓Error line numbers - Exact location of syntax errors
- ✓Error descriptions - Clear explanation of what's wrong
- ✓Syntax highlighting - Color-coded to identify different elements
- ✓Real-time validation - Checks as you type
- ✓Format on valid - Beautifies JSON once valid
Validate Your JSON Now
Check JSON syntax, find errors instantly, and format your data with our free validator!
Try JSON Validator →Frequently Asked Questions
What does "unexpected token" mean?
This usually means you have a syntax error like a missing comma, extra comma, or misplaced bracket. Check the line number provided.
Can I validate JSON in my code editor?
Yes! VS Code, Sublime Text, and most modern editors have built-in JSON validation. However, online validators often provide better error messages.
Is JSON5 valid JSON?
No. JSON5 allows trailing commas and single quotes, but these features are not valid in standard JSON. Use strict JSON validators to ensure compatibility.