Paste messy or minified JSON and get it back cleanly indented, or collapse it to a single line — instantly, in your browser. GhostDev validates the JSON as it formats, so a misplaced comma or unquoted key is flagged with the exact parser error instead of failing silently. Nothing is uploaded; your payload never leaves the tab, which makes it safe for API responses and config that you'd never paste into a random online beautifier. Free, no signup, no ads on the tool.
JSON's specification is stricter than most people expect, and nearly every parse failure comes from the same short list: a trailing comma after the last item, single quotes instead of double, an unquoted key, or a stray comment. None of those are legal JSON even though most of them are legal JavaScript, which is exactly why the mistake is so easy to make. Formatting the document also reveals structure — mismatched nesting becomes obvious once indentation is consistent.
Paste your JSON
Drop any JSON into the input box — minified, pretty, or somewhere in between.
Pick Beautify or Minify
Beautify pretty-prints with 2-space indentation; Minify strips all whitespace to one compact line. The output updates as you type.
Copy the result
Hit Copy to grab the formatted output. Everything ran locally — nothing was sent to a server.
Comments aren't valid JSON
// and /* */ are not part of the specification. Config formats that allow them — JSON5, JSONC, tsconfig.json — are extensions, and a strict parser will reject them.
Key order isn't guaranteed
The specification treats objects as unordered. Most implementations preserve insertion order in practice, but nothing requires it, so don't build logic that depends on it.
Large numbers can lose precision
JSON numbers are parsed as IEEE-754 doubles, so integers beyond about 9 quadrillion are silently rounded. APIs handling large IDs usually send them as strings for this reason.
Is my JSON sent to a server?
No. Parsing and formatting happen entirely in your browser with the native JSON parser. There's no upload endpoint — open DevTools → Network and confirm.
Does it validate the JSON?
Yes. If the input isn't valid JSON, the tool shows the parser's error message so you can find the problem instead of guessing.
Will it preserve the key order?
Yes — object keys are kept in their original order, — with the caveat that JavaScript reorders integer-like keys and collapses duplicates as the JSON parser returns them.
Is there a size limit?
Only your browser's memory. Typical API responses and config files format instantly; very large documents may be slower to render.
Can it minify as well as beautify?
Yes — switch to Minify to collapse the JSON to a single line with no extra whitespace, ideal for embedding in code or env vars.
Why does my JSON fail to parse?
In order of likelihood: a trailing comma, single quotes instead of double quotes, an unquoted key, a comment, or a raw newline inside a string. The error position usually points just past the real problem.
Every GhostDev tool runs entirely in your browser. Your file is never uploaded — there's no upload endpoint to send it to.