JSON Validator

Paste JSON to check that it is valid. If it is not, you get a clear message with the exact line and column where the problem is, such as a trailing comma or a missing quote. Valid JSON opens as a formatted tree. Nothing you paste leaves your browser.

JSON Input

Formatted JSON

Your JSON output will appear here.

How to use the JSON Validator

Paste your JSON into the input box, or pick the "Invalid JSON" example to see how errors are shown.
Click Format JSON. Invalid JSON shows an error with its line and column; valid JSON opens as a tree.
Fix the error at that position and click Format JSON again until the JSON is valid.

Features

Strict validation against the JSON standard (RFC 8259)
Error messages with the exact line and column, in every browser
Valid JSON is formatted and shown as a searchable tree
Statistics for valid JSON: keys, value types, nesting depth and size
Runs entirely in your browser, so private data stays on your device

Frequently asked questions

What are the most common JSON errors?: Trailing commas after the last item, single quotes instead of double quotes, keys without quotes, comments, and missing closing brackets or braces. JSON allows none of the first four.
Why does the error point to a line after the real mistake?: The validator reports where reading had to stop. A missing comma or bracket is often only noticed at the next value, so check the line shown and the one before it.
Can it check that my JSON has the right fields and types?: This page checks syntax: whether the text is valid JSON at all. To check fields, types and required values, use the JSON Schema Validator.
Is my JSON uploaded to validate it?: No. Validation happens in your browser, and the JSON you paste is never sent to a server.