Support: JSON Formatter

Tell us what happened. Include which page you were on and what you expected to see. Most answers go out within a business day.

Common questions

Is my JSON sent to a server?

No. Formatting and validation happen in your browser on your own device. Nothing you paste is sent to us or stored, so it is safe to use with private data.

How do I find the error in my JSON?

Press Format. If the JSON is not valid, the tool shows the line and column where reading stopped, with a pointer under the problem character, and moves the cursor there. The mistake is at that point or just before it, such as a missing comma or quote.

What does Fix common mistakes change?

It removes comments and trailing commas, changes single-quoted strings to double-quoted, adds quotes around unquoted keys, and turns Python's True, False and None into true, false and null. It tells you what it changed, and you can undo it.

What is the difference between formatting and minifying?

Formatting adds line breaks and indentation so people can read it. Minifying removes all unnecessary spaces and line breaks to make the file as small as possible for sending or storing. Both contain exactly the same data.

Why did a long number change?

Browsers, and most programming languages, store numbers with about 15 to 17 significant digits. Longer numbers, like some IDs, get rounded. The tool warns you when this happens. Keep such IDs as strings in quotes.

Does sorting keys change the data?

No. JSON objects have no meaningful key order, so sorting only makes them easier to read and compare. Arrays keep their order.

Is there a size limit?

No fixed limit. Files of several megabytes work well; very large files depend on your device's memory.