JSON Validator
Free JSON validator. Validate JSON syntax, format and beautify JSON, and catch errors instantly. Supports nested objects and arrays. Runs in your browser.
About the JSON Validator
The JSON Validator runs entirely in your browser. Your data stays on your device — there's no upload to any server.
Free JSON validator. Validate JSON syntax, format and beautify JSON, and catch errors instantly. Supports nested objects and arrays. Runs in your browser. Free, no sign-up, privacy-first.
How to use the JSON Validator
Validate JSON data and pinpoint syntax errors instantly. Essential for debugging API responses, configuration files, and data payloads.
- 1
Paste your JSON
Type or paste your JSON into the input area. The validator checks it in real time.
- 2
Review the result
Valid JSON shows a success message. If invalid, the error type and location are highlighted.
- 3
Fix and re-validate
Correct the highlighted error and the validator updates automatically as you type.
Tips
- •Common JSON errors include trailing commas, single quotes, and unescaped characters in strings.
- •Use the JSON formatter tool to auto-beautify valid JSON for easier reading.
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Frequently Asked Questions
Is the JSON validator free?
Yes, our JSON validator is completely free with no sign-up required. You can validate unlimited JSON data instantly.
How does the JSON validator work?
Paste your JSON and the tool parses it in your browser. If there's an error, it highlights the exact location and shows a helpful message explaining what went wrong.
Are my JSON files uploaded to a server?
No. All validation happens locally in your browser. Your data never leaves your device, ensuring complete privacy.
Does it work with large JSON files?
Yes. Since it runs in your browser, performance depends on your device. Most JSON files up to several MB are validated instantly.