How to Format and Beautify Messy JSON from an API Response
You fire off a request with curlor hit an endpoint in the browser, and the response comes back as one enormous, single-line blob — no line breaks, no indentation, just {"data":[{"id":1,"name":"…"}]} stretching off the edge of your terminal. Reading it is hopeless, and spotting the one field you actually care about is worse.
The fix is to beautify it: re-indent the structure so the nesting is visible. Here is how to do it in seconds.
How to format and beautify messy JSON
QuickWand's free JSON Formatter runs entirely in your browser, so your API payload — including any tokens or personal data inside it — is never uploaded to a server.
- Open the JSON Formatter.
- Paste the raw API response into the input box — the whole single-line blob, exactly as it came back.
- Click Format. The tool re-indents everything with proper nesting and line breaks so arrays and nested objects line up and become scannable.
- Copy the beautified output, or click Minifyif you need to collapse it back into one compact line — handy for pasting into a config or a test fixture.
Why API responses come back minified
Most APIs serialize their responses with no extra whitespace on purpose. Every space and newline is a byte, and across millions of requests those bytes add up to real bandwidth and latency. A server calling JSON.stringify(data) with no third argument produces the compact form; passing JSON.stringify(data, null, 2)is what adds the two-space indentation you see when something is “pretty.”
Beautifying is purely cosmetic. It changes only whitespace — the keys, values, types, and ordering are identical. So you can format a response to read it, then minify it again with zero risk of altering the data.
It validates while it formats
A formatter has to parse the text before it can re-indent it, so if the JSON is broken it will tell you. A truncated response, a stray NaN, or single quotes instead of double quotes will all surface as a parse error rather than silently producing garbage. If you hit one of those, our companion guide on fixing JSON syntax errors walks through the usual suspects.
Cleaning up the values, too
API payloads often carry encoded data inside string fields. You might find a URL crammed with %20 and %3D sequences, or a field holding a Base64 blob. Once the JSON is readable you can pull those values out and run them through the URL decoder or the Base64 decoder to see what they really contain.
Paste, format, read. That is the whole loop — and because it all happens locally, you never have to think twice about pasting a response that contains a session token.