JSON Formatter & Validator

Format, minify and validate JSON instantly. Free, private and instant.

About the JSON Formatter & Validator

JSON is the standard text format APIs use to exchange data. Minified JSON is hard to read, so a formatter indents it and a validator points to the exact syntax error.

When to use it

Use it when debugging API responses, checking config files, or shrinking JSON before sending it over the network.

How JSON formatting works

Formatting parses the text into a data structure and writes it back with consistent indentation. If parsing fails, the text is not valid JSON, so the tool can report the problem instead of guessing. Formatting changes only whitespace, never keys or values.

Common JSON errors

The most frequent mistakes are a trailing comma after the last item, single quotes instead of double quotes, unquoted keys and comments. JSON allows none of these. It also has no undefined or NaN values.

Format or minify

Formatted JSON is for people: easy to read and review. Minified JSON removes optional whitespace to save bytes when data travels over a network. Both versions represent identical data.

Tips

Validate JSON before pasting it into a config file, and keep tokens or secrets out of shared screenshots. This tool runs in your browser, so what you paste is not uploaded.

How to use the JSON Formatter & Validator

1. Enter or paste your input in the fields above.
2. The result updates as you type, or press Run.
3. Press Copy to copy the output.

Frequently asked questions

Is the JSON Formatter & Validator free?

Yes. It is completely free, with no signup and no usage limits.

Is my data uploaded anywhere?

No. Everything runs locally in your browser, so what you type never leaves your device.

Does the JSON Formatter & Validator work on mobile?

Yes. The tool is responsive and works on phones, tablets and desktops.

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