Sort JSON Object Keys in Your Browser

Sort object keys explicitly

Paste strict JSON or open one UTF-8 .json file. Select Sort keys to produce a separate result. Defaults are ascending, case sensitive, recursive and two spaces with LF. Four spaces, a tab and minified output are also available. Loading an example or changing options does not start processing.

The shared example is:

{"z":{"2":"dos","10":"diez"},"a":[{"b":2,"a":1}]}

With the defaults:

{
  "a": [
    {
      "a": 1,
      "b": 2
    }
  ],
  "z": {
    "10": "diez",
    "2": "dos"
  }
}

Text order, case and scope

Decoded keys are compared ordinally by UTF-16 units. Numeric-looking keys are text: "10" precedes "2" ascending. Case sensitive ascending order is A,B,a,b; Ignore case A–Z gives A,a,B,b, breaking ties by the original key. Descending reverses the whole order, including ties. Accents are not folded: É and é remain distinct, and Unicode is not normalized.

Recursive mode sorts every object, including objects inside arrays. Root object only leaves descendant object members in their source order; if the root is an array, it sorts no objects. Arrays always keep their length and element positions. Primitive roots, empty objects and arrays are valid; with no eligible objects, formatting still applies and an informational notice appears.

Preserve values and reject ambiguous input

Strings, decoded keys, booleans, null and structures retain their values. Original numeric tokens 9007199254740993, 0.10000000000000001, -0 and 1E+02 are preserved exactly. A precision warning describes the approximate internal parser value, not rounding in the output. Numbers outside the parser range, such as 1e400, fail explicitly.

{"a":1,"\u0061":2} fails because the decoded key occurs twice; no occurrence is silently overwritten. Comments, JSONC, JSON5 and malformed JSON are rejected. One initial BOM is removed with a notice, while a second BOM is a syntax error. Output is reformatted, with LF, no BOM and no final newline; original whitespace and string escape spelling are not preserved. This is not JCS or cryptographic canonicalization for signatures.

Limits, complete exports and local processing

Files may contain up to 4,000,000 original bytes. Input is limited to 1,000,000 UTF-16 units, depth to 200 containers, source nodes to 100,000 and output to 2,000,000 UTF-16 units. Parsing, serialization and key ordering each have a 1,000,000-unit work budget; long key prefixes or deep indentation can fail before a size ceiling. These maxima are not guaranteed simultaneously. Processing times out after 15 seconds; an output retrieval has a 5-second timeout. At most 100 diagnostics and a 20,000-unit preview are shown.

The truncated preview may be incomplete JSON. Copy all and Download JSON retrieve the full result, including all numeric digits. If clipboard access fails, use the complete manual-copy field or Copy again. Downloads use json-sorted.json, UTF-8 and JSON MIME type.

All processing stays in the browser: no uploads, remote URLs or document storage. You can cancel while keeping input and options. Editing, selecting a file, changing options or clearing invalidates prior results and exports. Clear keeps the chosen options. JavaScript and a Worker-capable browser are required.