JSON Validator
JSON Validator
Check whether your JSON is syntactically valid with the exact line and column of any error pinpointed.
How to Use JSON Validator
- 1.Paste your JSON Paste the JSON you want to check into the input area.
- 2.Validation runs instantly The validator checks your JSON as you type or paste - no button press needed.
- 3.Read the result If valid, you see a green confirmation. If invalid, the exact line, column, and error message are shown.
- 4.Fix the errors Use the reported line and column to find the issue, or paste into JSON Repair for automated fixing.
JSON Validator & JSON Developer Standards
JSON is the standard format for web APIs and modern applications. Using the JSON Validator helps you check syntax, catch formatting errors, and keep your data clean and readable.
Zero-Server Security
All data entered into JSON Validator runs directly inside your browser sandbox. Nothing is ever sent across the network or saved on remote servers.
Clean & CI/CD Ready
Well-formatted JSON prevents runtime syntax bugs, makes code reviews easier, and ensures smooth API data exchange.
JSON Validator Frequently Asked Questions
What makes JSON invalid?
Common causes include: trailing commas after the last item in an object or array, single-quoted strings instead of double-quoted, unquoted keys, missing commas between items, incorrect nesting of brackets or braces, and unescaped control characters in strings.
Does this validator support JSON5 or JSONC?
No. This tool validates strict JSON per RFC 8259. JSON5 (which allows comments and trailing commas) and JSONC (JSON with Comments) are not valid JSON. Use JSON Repair to strip those extensions and produce valid JSON.
Can I validate a JSON Schema file?
A JSON Schema file is just a JSON document. The JSON Validator checks that it is syntactically valid JSON. To validate the schema itself against the JSON Schema specification, use the JSON Schema Validator tool.
Is there a size limit?
The validator runs in your browser with no upload. You can validate JSON files of any size, though very large files may take a moment to process.
Why does my JSON show as invalid when it looks correct?
Check for: a trailing comma after the last property in an object or array, a key without quotes, a value using undefined or a JavaScript function, or a BOM (byte order mark) at the start of the text. Copy the error line number to find the exact issue.
Can this tool handle large, complex JSON payloads?
Yes. Because the tool operates directly inside modern V8 JavaScript execution engines, it easily processes complex multi-megabyte payloads containing thousands of nested keys with negligible latency.
Are my proprietary payloads or secrets stored or cached?
No. BeYourTools implements zero tracking, zero telemetries, and zero database persistence. Everything stays strictly inside your browser memory and disappears the moment your tab is closed.