JSON Validator & Linter

Validate your JSON data against syntax standards. Find missing commas, brackets, and quotes instantly.

Free JSON Syntax Checker

Broken JSON is the #1 cause of API failures. Our online validator parses your code to ensure it meets strict JSON standards, highlighting exactly where the error occurred.

Error Spotting

Pinpoints line numbers where syntax errors exist, so you don't have to hunt for a missing comma.

RFC Support

Validates against official JSON standards (RFC 8259) for maximum compatibility.

Private

Runs entirely in your browser. Sensitive config or data is never sent to a backend.

Why Validate JSON?

JSON is strict. A single trailing comma or unquoted key can crash an application.

  • Common Errors

    Trailling commas, single quotes (JSON needs double), and missing brackets.

  • API Development

    Ensure the payload you send to a server is perfectly formatted.

Steps to Validate

1

Paste JSON

Input your code into the editor.

2

Check

The tool runs instantly. It will show "Valid JSON" or explain the error.

3

Fix

Correct the highlighted issue and re-validate.