Free JSON FormatterValidate, beautify and explore JSON.

Paste JSON or open a file to check it, pretty-print it or minify it. Mistakes are shown with their line and column.
Browse the result as a tree, sort the keys and copy the path to any value.

Exact big numbersError line & columnLarge files

No sign-up No upload No size limit

Input

Or try an example

Paste JSON to check and format it.

Indent Sort keys A–Z

Your JSON stays on your device.

THREE SIMPLE STEPS

How to format JSON

Paste or open your JSON

Paste it into the box or open a .json file. It is checked as you type.

Fix or format

If something is wrong you see the line and column. If it is valid, choose the indent, sort the keys or minify.

Copy or download

Copy the result, download it as a file, or switch to the tree to explore it and copy the path to any value.

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JSON Formatter FAQ

Is this JSON formatter free?

Yes. Format and check as much JSON as you like with no account and no limit.

Is my JSON uploaded?

No. Everything runs in your browser, so API responses, configs and anything private stay on your device.

How does it show errors?

A mistake is reported with its line and column, a short explanation and the line itself with a marker. “Go to error” jumps to it in the box. Common slips such as trailing commas, single quotes, comments and unquoted keys are named.

Are big numbers kept exact?

Yes. Numbers are copied exactly as you wrote them, so an ID like 12345678901234567890 or a value like 1.10 is not rounded or changed. Many tools lose digits beyond 15 or 16 places.

What happens to duplicate keys?

All copies are kept in the order you wrote them, and you are warned about the repeat. Many programs keep only the last value, so it is worth fixing.

Can it handle large files?

Yes. Files of several megabytes format in a fraction of a second, and the tree only draws the rows you can see, so scrolling stays smooth.

What does sort keys do?

It puts the keys of every object in A–Z order. Lists keep their order, since the order of items in a list can matter.

Does it accept comments or trailing commas?

No. It checks against standard JSON, which allows neither. The error tells you where to remove them.

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