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JSON Viewer

Lint & validate JSON

JSON Validator

Check whether JSON is valid while you type. Every syntax error is underlined on its exact line and column, explained in plain English, and often fixable in one click.

InputWaiting for JSON

The beautified JSON and tree appear here as soon as your input is valid.

0 B0 linesLn 1, Col 1

Load JSON from a URL

Your browser fetches it directly; it does not pass through our servers. The site must allow cross-origin requests.

How it works

How to use the JSON Validator

  1. 01

    Paste the JSON you want to check, or drop in a file.

  2. 02

    Read the status bar. A green “Valid JSON” means you are done; otherwise each problem is listed with its line and column.

  3. 03

    Click an error to jump to it, or press Fix to repair trailing commas, quotes, comments and more.

FAQ

Frequently asked questions

What are the most common JSON errors?

Trailing commas after the last item, single quotes instead of double quotes, unquoted keys, comments, missing commas between items, and unclosed brackets. Our guide to common JSON errors covers each one with an example.

Does the validator check against a JSON Schema?

Not yet. It checks that the text is valid JSON syntax as defined by RFC 8259. Schema validation is on our roadmap.

Why does my JSON fail here but work in JavaScript?

JavaScript object literals allow things JSON does not, such as single quotes, unquoted keys, trailing commas and comments. Strict JSON parsers in other languages will reject those too.

Is my JSON uploaded to a server?

No. All parsing, formatting and validation happens in your browser with JavaScript. Nothing you paste or open is sent to us or stored on a server. Share links keep the JSON inside the URL fragment (after the #), which browsers never send to servers.

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