JSON Validator
Validate JSON as you type with exact line and column positions for missing commas, quotes and brackets. Free and browser-based.
Awaiting input
What is a JSON validator?
A JSON validator answers one question: is this text valid JSON according to RFC 8259? It checks the grammar — commas, quotes, brackets, escapes, numbers — and points at the first position that breaks the rules.
That check matters before parsing in production: a trailing comma or a single-quoted key fails the whole payload, and catching it here is faster than reading a stack trace later.
How to validate JSON
- Paste the JSON you want to check.
- Read the status bar — it reports Valid or the first syntax error.
- If there is an error, jump to the reported line and column.
- Fix the issue and watch the status update as you type.
- Copy the validated document into your code or config once the status is green.
Validation examples
Trailing comma
{
"a": 1,
"b": 2,
}Invalid — unexpected } at line 4, column 1
Single quotes
{'name': 'ursa'}Invalid — property names must use double quotes
JSON validator vs JSON Schema
| Dimension | JSON validator | JSON Schema validator |
|---|---|---|
| Checks | Syntax only | Syntax plus shape and types |
| Answers | Is this JSON? | Does this JSON match my contract? |
| Speed | Instant, single pass | Slower, walks the schema |
| Use it when | Before parsing anything | Before trusting a payload |
FAQ
Frequently Asked Questions & Specs
What errors are detected?
Syntax problems such as missing quotes, trailing commas, unmatched braces and invalid escapes, reported from jsonc-parser.
Does it check JSON Schema rules?
No — this page checks JSON syntax. Use the Schema generator to derive a schema from valid data.
JSON Validator
- Errors point at the exact line and column so you can fix them fast.
- Use Fix escapes when the document contains invalid escape sequences or raw control characters.
- Validation never leaves your device.