JSON Formatter and Minifier
Beautify messy JSON into readable, indented text or minify it down to a single line.
This tool runs entirely in your browser. Your JSON is never uploaded to any server.
How to use this tool
Pick a mode at the top. Choose Beautify to turn compact or messy JSON into clean,
indented text that is easy to read, or choose Minify to strip every space and line break
so the data is as small as possible. Paste your JSON into the input box, then press the action button.
If the text is valid JSON, the result shows in the output box and you can copy it or download it as a
.json file. If something is wrong, a clear error message tells you what failed so you can fix it.
How the JSON beautifier works
Both modes start the same way: the raw text is parsed with the browser's built-in
JSON.parse, which both validates the structure and converts it into a real JavaScript value.
That value is then turned back into text with JSON.stringify. Passing null and the
number 2 as the last two arguments tells the beautifier to indent each level with two spaces.
Leaving those arguments off produces the smallest possible single-line output for the minifier. Because the
JSON is parsed first, any invalid input is caught before formatting and reported as an error.
A real example
Suppose you paste {"id":7,"items":["pen","pad"],"active":true} and choose Beautify.
The tool returns:
Switch to Minify and feed that indented version back in, and you get the compact original again:
{"id":7,"items":["pen","pad"],"active":true}. The data is identical; only the spacing changes.
Common questions
What does a JSON beautifier actually do?
It re-formats valid JSON with consistent indentation and line breaks so the structure is easy to scan. The underlying data does not change, only the whitespace and layout.
Why would I minify JSON?
Minifying removes all unnecessary spaces and newlines, which shrinks the file size. That is useful for API payloads, configuration files, and anything sent over a network where smaller is faster.
Why am I seeing a parse error?
The text is not valid JSON. Common causes are trailing commas, single quotes instead of double quotes around keys and strings, comments, or unquoted keys. The error message points to roughly where the problem is.
Is my data safe to paste here?
Yes. All parsing and formatting happen locally in your browser using native JavaScript. Nothing you paste is sent to a server or stored anywhere.
Can it handle large JSON files?
It can handle fairly large input, but very large files depend on your device's memory since everything runs in the browser tab. For multi-megabyte files, a desktop browser works best.