JSON Validator
Validate JSON syntax and check for errors instantly. Free, no sign-up required.
All processing happens in your browser. Your input never leaves your device.
Why Use Our JSON Validator?
Instant Validation
Paste JSON and get validation results in milliseconds. No waiting, no processing delays.
Detailed Errors
Get exact error messages with line numbers and column positions. Know exactly where and what went wrong.
Auto-Fix Issues
Automatically fix trailing commas, single quotes, and comments with one click. Save time debugging.
Free Forever
No limits, no sign-up, no ads. Validate as much JSON as you want, whenever you want.
How to Validate JSON Online
Paste JSON
Paste your JSON code into the input area above. Works with objects, arrays, and any nested structure.
Click Validate
Click the Validate JSON button. Your JSON is instantly parsed and checked for syntax errors.
Review Results
See detailed results: structure stats for valid JSON, or exact error messages with line numbers for invalid JSON.
JSON Validator vs JSON Beautifier
A JSON validator checks whether your JSON is syntactically correct. It reports errors with line numbers and can detect common mistakes like trailing commas, single quotes, and comments that are not allowed in standard JSON.
A JSON beautifier takes valid JSON and reformats it with proper indentation and spacing. The goal is human-readable code, not error checking.
Use the validator first to make sure your JSON is correct, then use the JSON Beautifier to format it for readability. Both tools are free on Linkyhost.
Common JSON Errors
Trailing Commas
A comma after the last item in an object or array is valid in JavaScript but not in JSON. Our validator detects this and can remove them automatically.
Single Quotes
JSON requires double quotes for strings and keys. Single quotes are a JavaScript convention that will cause a parse error in strict JSON.
Unquoted Keys
All keys in JSON must be wrapped in double quotes. Writing { name: "value" } instead of { "name": "value" } is invalid.
Comments
Standard JSON does not support comments. Both single-line (//) and block comments (/* */) will cause parse errors. Use our auto-fix feature to strip them out.
Frequently Asked Questions
How do I validate JSON online?
Paste your JSON into the input area and click Validate JSON. The tool instantly checks your code for syntax errors and shows detailed results.
What are the most common JSON errors?
Trailing commas, single quotes instead of double quotes, unquoted keys, and comments. All of these are valid in JavaScript but not in strict JSON. Our validator detects and can fix these automatically.
What is the difference between a JSON validator and a JSON beautifier?
A validator checks if JSON is syntactically correct. A beautifier formats valid JSON with proper indentation. Use the validator to find errors, the beautifier to improve readability.
Can the JSON validator fix errors automatically?
Yes. Click the Fix Common Issues button to automatically remove trailing commas, replace single quotes with double quotes, and strip comments from your JSON.
Is the JSON validator free?
Yes. Completely free with no limits. No sign-up or account required. Just paste your JSON and click Validate.