JSON Validator

Check JSON syntax instantly, find parse errors, then format valid JSON in one privacy-first tool.

Syntax checker Line hints Client-side
Input
Output

Paste JSON and tap Validate JSON above

Ready Lines: 0 Size: 0 B Indent:
Runs entirely in your browser. No data sent to any server.

Paste or upload JSON to validate syntax, pinpoint parse errors, and format valid JSON without sending data to a server.

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Frequently Asked Questions

Is this JSON validator free to use?

Yes, the JSON validator is free and does not require an account.

Does the validator upload my JSON?

No. Validation runs in your browser with JavaScript, so pasted JSON is not sent to a server.

What JSON errors can it find?

It catches standard JSON syntax errors such as trailing commas, single quotes, unquoted keys, missing brackets, invalid escapes, and incomplete input.

Does this validate JSON Schema rules?

This page validates JSON syntax. Use the JSON Schema Validator to validate data against a schema.

Can I format JSON after validating it?

Yes. Valid JSON can be formatted, minified, copied, downloaded, or explored in the tree view.