How to Use the JSON Validator

Paste your JSON into the input field.

The tool parses it immediately and returns either a valid confirmation or a precise error message indicating the line and position of the problem.

Fix the flagged issue, re-paste, and validate again until the document is clean.

What Is JSON Validation?

JSON validation checks a document against the JSON specification (RFC 8259) to confirm it is syntactically correct. Common issues include trailing commas, unquoted keys, mismatched brackets, single-quoted strings, and comments — none of which are permitted in standard JSON. A validator parses the document and reports the first error it encounters along with its location, so you can fix problems precisely rather than scanning the document manually. This tool validates syntax only — it does not validate against a JSON Schema. For formatting valid JSON, use the JSON formatter & validator.

When to Use This Tool

Before sending API requests — Catch syntax errors in request bodies before they hit your endpoint and return a cryptic 400 error.

Debugging config file errors — Validate JSON config files (package.json, tsconfig.json, etc.) that fail to parse at runtime.

Checking third-party data — Verify that JSON received from an external source is well-formed before processing it.

Learning JSON syntax — Use the error messages to understand exactly which JSON syntax rules are being violated.

Related Tools

• JSON formatter & validator
• JSON minifier
• JSON escape
• YAML validator
• XML validator