JSON Formatter & Validator

Pretty-print, minify and validate JSON, with clear error messages.

Loading JSON Formatter…

How to use JSON Formatter

Paste your JSON into the input.
It is validated as you type, and an error message shows exactly what is wrong.
Choose a 2 or 4 space indent, or minify it to a single line.
Copy the result, or edit it directly in the formatted view.

About JSON Formatter

Paste raw or minified JSON and get it back pretty-printed with consistent indentation, or collapsed onto a single line. The formatter validates as it goes, so a stray comma or unbalanced brace is flagged with the exact parser message.

Everything runs locally using the browser's native JSON engine, so even large payloads format instantly and are never uploaded.

What people use it for

Beautify an API response copied from the network tab for easier reading.
Minify a config blob before embedding it in code or a query string.
Validate hand-written JSON and pinpoint the exact syntax error.
Normalize indentation across a team's test fixtures.

Frequently asked questions

What indentation can I choose?

Two spaces, four spaces, or minify to a single line. The output updates live as you type.

Will it repair invalid JSON?

It won't auto-fix, but it shows the precise error message so you can correct it fast. Trailing commas and single quotes are the usual culprits.

Is there a size limit?

Only your browser's memory; multi-megabyte documents format fine since nothing is uploaded.

Is it private?

Every calculation happens on this page, in your own browser. Your input is never sent to a server and never logged, which also means the tool keeps working when you are offline.