JSON Formatter
Format minified JSON with readable indentation.
Open toolDeveloper Tools
JSON Validator
Validate JSON and pinpoint syntax errors. Your input stays in this browser during processing.
Private local processing
Your text and settings stays in this browser.
About JSON Validator
Check whether entered text is valid JSON and surface the browser parser's exact syntax error when it isn't.
What the result contains
A clear valid-JSON confirmation or the browser parser's syntax error.
Accepted input
- JSON
- PLAIN
- TXT
How to use JSON Validator
- Paste the JSON text you want to check.
- Run validation and review the pass or fail result.
- Note the reported error location and correct that section first if it fails.
- Re-validate until the JSON parses cleanly.
Practical example
Check a configuration payload before sending it to an API.
Check your result before using it
Use the reported location to inspect the surrounding syntax, including a comma immediately before a closing bracket or an unescaped quotation mark. A document can be valid JSON and still fail your application's schema: a required field may be missing or contain the wrong type. After syntax validation, check required properties and value constraints separately. Do not infer that a valid document is safe or trustworthy.
When to use JSON Validator
- Confirm a configuration payload is valid before sending it to an API
- Check a hand-edited JSON file for a typo before committing it
- Verify JSON pasted from another tool didn't lose a closing bracket
Important limitations
- Validation covers JSON syntax, not an external JSON Schema.
- Duplicate object keys may be accepted by parsers with the last value taking precedence.
Troubleshooting JSON Validator
The error location is difficult to understand
Format smaller sections or use JSON Formatter after correcting the first reported syntax error.
Private local processing
The text and settings is processed on this device and is not uploaded to MyFileNest. Closing or refreshing the page clears the active session.
Frequently asked questions
Practical limit: Large text or structured-data inputs can respond more slowly in the browser. Verify generated output before using it in a production workflow.