JSON Beautify — Pretty-Print and Format JSON Online

🔒 Runs in your browser — nothing is sent to a server

JSON beautify any compact or minified JSON into a clean, readable structure with proper indentation in a single click. Paste a one-line API response, a config snippet pulled from a log line, or any blob of compact JSON, and this JSON formatter validates the syntax and pretty-prints the result with 2-space indents. Errors point at the offending position so you can fix malformed JSON instantly. Everything runs 100% inside your browser; your input never leaves your device, nothing is uploaded, logged or sent to any server.

Two-pane view: input and output side by side
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When to use a JSON beautifier

You reach for a JSON beautifier any time a one-line API response, a stringified config blob in a log line, or a copy-pasted JWT payload arrives unreadable: debugging an HTTP error, comparing two responses with `diff`, walking through a deeply nested CDN settings file, demoing what a webhook payload looks like in a code review, or simply preparing JSON for inclusion in documentation. The two-space pretty-print form is what most readers expect, what GitHub renders inline, and what JSON style guides prescribe. Running the format in a browser-local tool keeps the payload off remote servers — important when the JSON contains secrets, tokens or PII.

How JSON beautifying works under the hood

JSON beautifying is a two-step pipeline. First the input string is parsed into an in-memory JavaScript value through `JSON.parse` — this step also validates the syntax, so any error here surfaces immediately as a clear "Unexpected token" message with a position. Second, that value is serialised back to a string with `JSON.stringify(value, null, 2)`, where the third argument tells the runtime to insert two spaces of indentation per nesting level and a line break after every comma, opening brace and opening bracket. The original semantics are preserved exactly: keys keep their order, numbers their precision, strings their escapes. The whole pipeline runs natively inside the browser engine — so a multi-megabyte JSON document beautifies in milliseconds without leaving your tab.

Examples

Input
{"id":42,"user":"alice@free-converter.online","roles":["admin","auditor"]}
Output
{
  "id": 42,
  "user": "alice@free-converter.online",
  "roles": [
    "admin",
    "auditor"
  ]
}
JSON beautify — minified API response with nested fields
Input
{"products":[{"sku":"FC-001","price":29.99},{"sku":"FC-002","price":49}],"total":2}
Output
{
  "products": [
    {
      "sku": "FC-001",
      "price": 29.99
    },
    {
      "sku": "FC-002",
      "price": 49
    }
  ],
  "total": 2
}
Pretty print JSON — array of products with prices
Input
{"tool":"json beautify","useCase":"format minified JSON","online":true}
Output
{
  "tool": "json beautify",
  "useCase": "format minified JSON",
  "online": true
}
Format JSON online — payload that names the tool itself
Input
[1,"two",true,null,{"three":3}]
Output
[
  1,
  "two",
  true,
  null,
  {
    "three": 3
  }
]
Beautify JSON online — array with mixed JSON types

FAQ

How do I beautify a JSON string?

Paste the minified or compact JSON into the input above and click Beautify. The JSON formatter parses your input via the browser's native `JSON.parse`, then re-emits it with `JSON.stringify(value, null, 2)` — a clean two-space indent with line breaks for nested objects and arrays. If the input is invalid, you get the parser's error message instead of mangled output.

What is JSON beautifying or pretty-printing?

JSON beautifying — also called pretty-printing — reformats compact JSON by adding indentation, line breaks and consistent spacing so a human can read it. The data is unchanged: the same keys, the same values, the same structure, just formatted for visual scanning. Most JSON beautifiers default to two-space indentation, which is the convention adopted by GitHub and Prettier.

What indentation does this JSON formatter use?

Two-space indentation — the convention used by Prettier, GitHub, ESLint and most JSON style guides. Two spaces is dense enough to keep deeply nested structures on screen, while still distinguishing every level. Tabs and four-space indents are valid JSON too, but two-space is what the wider ecosystem expects, and it is what `JSON.stringify(value, null, 2)` emits in every modern runtime.

How do I pretty-print JSON in JavaScript or Python?

In JavaScript, `JSON.stringify(value, null, 2)` does it natively — pass the indent count as the third argument. In Python, `json.dumps(value, indent=2)` is the equivalent. Both produce the same output as this online JSON beautifier. The browser-side tool is just a convenient UI on top of the same `JSON.stringify` call your runtime already exposes.

Why does my JSON fail to parse?

The most common causes are trailing commas (`{"a":1,}` is invalid in strict JSON), single quotes around keys or strings (JSON requires double quotes), unescaped newlines or tabs inside string values, and JavaScript-style comments — JSON has no comment syntax. Pasting JavaScript object literals or jq output that contains JS-only syntax will fail; convert it to strict JSON first.

How is JSON beautify different from JSON minify?

JSON beautify and JSON minify are exact opposites. Beautify adds whitespace — line breaks, indentation, spaces around colons — to make the JSON easy to read. Minify strips every byte that is not strictly necessary, producing the shortest valid representation. The data is identical in both directions; only the formatting differs. Use beautify for debugging, minify for transport.

Is it safe to paste sensitive JSON into this beautifier?

Yes — the JSON beautifier runs entirely in your browser using the native `JSON.parse` and `JSON.stringify` APIs. Your input and the formatted output stay on your machine; nothing is uploaded, logged or cached. Safe for API responses with secrets, JWT payloads, internal config files and any blob you would not want a remote service touching.

Glossary

JSON (JavaScript Object Notation)

JSON is a lightweight, text-based data format that represents structured data as nested objects, arrays, strings, numbers, booleans and null. Defined by RFC 8259 and ECMA-404, JSON is the de-facto wire format for HTTP APIs, configuration files, package manifests and IPC. A JSON beautifier reformats compact JSON without changing its meaning — only the whitespace differs between minified and pretty-printed forms.

Pretty-print

Pretty-print is the operation of formatting structured data — JSON, XML, source code — with whitespace and indentation so a human can read it. For JSON specifically, pretty-printing means inserting line breaks after commas and braces and indenting every nesting level, usually by two spaces. The resulting JSON parses identically to the compact form because JSON ignores any whitespace outside of strings.

JSON formatter

A JSON formatter is any tool or function that takes a JSON value and emits it as a string with controlled whitespace. Browser `JSON.stringify(value, null, 2)`, Python `json.dumps(value, indent=2)`, Prettier and `jq .` are all JSON formatters. Browser-local formatters like this page have a security advantage: the JSON never leaves the tab, so secrets in the payload are never exposed to a server.

JSON indent

JSON indent is the number of spaces (or tabs) used to align nested levels in a pretty-printed JSON document. Two spaces is the most common choice, used by Prettier, GitHub and most style guides; four spaces and tab indents also occur. The browser `JSON.stringify` API accepts the indent as its third argument — a number for spaces, a string for any custom prefix.

Minified JSON

Minified JSON is JSON with every byte of optional whitespace removed: no line breaks between keys, no spaces after colons or commas, the entire document on one line. Minified JSON is what HTTP APIs ship across the wire because it is the smallest valid representation. A JSON beautifier reverses minification by adding back the readable whitespace.

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