Validate JSON online before sending API requests or committing config files. Paste JSON to confirm it parses, highlight error location, and fix trailing commas or quote issues fast.

JSON requires double quotes on keys and strings; single quotes and comments are invalid in strict JSON.

How to use this tool

Paste JSON into the editor. Fix reported errors until validation passes, then copy clean JSON.

Worked example

Example: API returns 400—validator shows a trailing comma on line 14 before you redeploy.

When to use this

Debugging webhook payloads.
Checking exported config before production.
Learning JSON syntax in tutorials.

Common mistakes

Trailing commas after last array/object item.
Unescaped newlines inside strings.
Using undefined or NaN (invalid in JSON).

json lint online
validate json file
json parse error line number

How it works

Paste JSON to validate syntax instantly. Invalid JSON shows parse errors with line and column when available. Validation works on your device.

Limitations

Validates JSON syntax only. Schema, business rules, and duplicate keys are not checked unless noted.

Privacy and file handling

Your data stays on your device and is not uploaded.

Related JSON Validator guides

These pages use the same json validator with guides tailored to specific search intents.

JSON Validator — general payment estimate
JSON Syntax Checker
Validate JSON Syntax
JSON Lint Checker
Check JSON Online

FAQ

Frequently asked questions

Does this format JSON?

Use JSON Formatter for pretty-print; this tool focuses on validity.

JSON5 or comments?

Standard JSON only—comments and unquoted keys will fail validation.

Large files?

Very large payloads may slow the browser; validate samples or use CLI for huge files.

Page last reviewed: July 5, 2026

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