Does it check my data against a schema?

No, it checks JSON syntax only, not a schema. Schema validation may be added in the future.

Does my data leave the browser?

No, validation happens entirely on your device.

What counts as invalid JSON?

Trailing commas, unquoted keys, single quotes and comments are common causes of invalid JSON.

JSON Validator

Check whether your JSON is valid. Paste it in and get an instant pass/fail result, with the exact line and column of any syntax error.

How to Use JSON Validator

1
Paste your JSON into the input box.
2
Click Validate.
3
See whether it's valid, and the exact line/column of any error.

JSON Validator Features

Pinpoints the line and column of syntax errors.
Runs entirely in your browser.
Instant feedback as you fix issues.

Why use Tool King?

Fast

No waiting rooms or sign-ups. Most files are ready in seconds.

Private

Files are processed in memory and discarded right after — never stored or shared.

Free

Every tool is free to use, with no hidden limits on the essentials.

Frequently Asked Questions

Related guides

A quick guide to formatting and validating JSON

Turn minified or messy JSON into something readable — and catch syntax errors fast.

Read guide

Related tools

JSON Formatter

Format and beautify your JSON data instantly.

JSON Viewer

Explore JSON data as a collapsible tree.

JSON to CSV

Convert a JSON array of objects into a CSV file.

JSON to YAML

Convert JSON data into YAML format.

Base64 Encoder/Decoder

Encode or decode text and files using Base64.

URL Encode

Percent-encode text for safe use in a URL.

Search tools...