What this validator checks
The validator checks whether your document follows JSON syntax: double-quoted keys and strings, valid commas, balanced brackets, and supported values. Inline markers help you find syntax problems in the editor.
JSON Validator
Check JSON syntax and locate parsing errors without uploading your data. Validation happens entirely in your browser.
Validator workspace
Paste JSON below to check its syntax and locate errors.
Valid JSON
This document contains valid JSON syntax.
JSON input
Validation runs locally in your browser. Your JSON never leaves this device.
Syntax validation, not JSON Schema
This tool answers whether a document is valid JSON. It does not enforce application rules such as required properties or value types defined by a JSON Schema.
JSON Validator FAQ
Why is my JSON invalid?
Common causes include trailing commas, single-quoted strings, unquoted property names, comments, or mismatched braces and brackets. The editor marks detected syntax errors as you type.
Is my JSON sent to a server?
No. Parsing and diagnostics run locally in your browser, so API responses, configuration files, and other sensitive documents stay on your device.