JSON Validator
JSON을 입력하면 자동으로 검증합니다.
Last updated: 2026 · Free online tool
What is JSON Validator?
Free online tool to validate JSON strings and pinpoint exact error locations
How to Use
- 1 Enter JSON — Paste the JSON string you want to validate into the text input area.
- 2 Select Validation Mode — Choose basic mode or detailed mode (duplicate key detection).
- 3 View Results — Check the valid/invalid result immediately in the top banner.
- 4 Fix Errors — If there are errors, refer to the line number, column number, and error message to fix them.
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Frequently Asked Questions
A JSON Validator is a tool that checks whether the entered JSON string follows valid syntax and reports exact error locations and messages.
Basic mode only checks for JSON syntax errors. Detailed mode additionally detects duplicate keys.
The JSON standard (RFC 8259) does not specify how duplicate keys should be handled, so different parsers process them differently. Removing duplicate keys prevents unpredictable behavior.
No. Only standard JSON (RFC 8259) is supported.
No. All validation is performed in the browser and no data is sent to a server.