Code Formatter

What this tool does

Paste a minified or messy HTML, CSS, JavaScript, or JSON snippet and get it back cleanly re-indented and line-broken. Leave the language on auto to detect it from the snippet, or pick one explicitly when auto-detect guesses wrong. Choose how many spaces to indent per nesting level, or switch to tabs.

Everything runs locally in your browser. For HTML, CSS, and JavaScript only the whitespace and line breaks change — nothing is renamed, reordered, or dropped. JSON is parsed, validated, and re-serialized with key order preserved.

Languages

• HTML — a forgiving tokenizer indents nested elements. Void tags (<br>, <img>, …) don't nest, and the contents of pre, textarea, script, and style are preserved verbatim.
• CSS — indents rule blocks and nested at-rules (@media { … }), normalizes prop: value; spacing, and preserves string literals and /* comments */.
• JavaScript — a token-aware pretty-printer re-indents blocks, statements, and object literals without changing what the code does.
• JSON — parsed and re-serialized. Invalid JSON is reported as an error instead of being silently mangled.

Worked example

Input (minified JSON):

{"name":"gizza","tags":["a","b"],"nested":{"x":1}}

Language: auto · Indent: 2 spaces

Output:

{
  "name": "gizza",
  "tags": [
    "a",
    "b"
  ],
  "nested": {
    "x": 1
  }
}

Switch Indent character to tab (or raise the space count to 4) to change the indentation width; switch Language to css, html, or javascript to format those instead.

Limits and edge cases

• This is a formatter, not a linter, minifier, or transpiler — it only re-whitespaces the input (JSON is re-serialized).
• Auto-detect is a best-effort heuristic. CSS vs JavaScript can be ambiguous; pick the language explicitly if the guess is wrong.
• JSON must be valid — trailing commas, comments, and single quotes are not standard JSON and produce an error. HTML, CSS, and JS are formatted best-effort even if slightly malformed.
• The contents of HTML pre, textarea, script, and style are left untouched, so code inside <script> is not itself re-indented.
• Comments and string contents are preserved, not reflowed. Long lines are not wrapped to a maximum width.
• Spaces-per-level is clamped to 1–8; tabs ignore the spaces setting.

FAQ