Sorted keys make it easier to diff two JSON files and to find specific fields quickly.

Does it sort nested objects too?

Yes. Keys are sorted recursively through every level of the object.

Does the order of array items change?

Array order is preserved; only object keys are sorted.

Are uppercase and lowercase keys sorted together?

Sorting uses JavaScript's default string order, which compares UTF-16 code units, so every uppercase ASCII letter (A-Z) comes before every lowercase one (a-z): "Zebra" sorts before "apple". Keys that are whole numbers come first of all, in numeric order.

Sort JSON Keys

Normalise JSON by sorting all keys alphabetically at every nesting level. Makes diffs cleaner and output predictable.

Input JSON

Output

FORMAT

INDENT

Tips

Paste JSON in the left pane. Output updates instantly.

Runs entirely in your browser

How it works

After JSON.parse turns your input into an in-memory tree, the tool walks every object and rebuilds it with keys in alphabetical order, recursing into nested objects and through array elements. Keys that are whole numbers (such as "2" or "10") always come first, in numeric order, because JavaScript objects keep them that way. JSON.stringify then emits the normalised tree with two-space indentation, or four spaces if you pick that option. The stable key order makes diffs between two JSON files line up cleanly so real changes stand out.

Example

Nested objects are sorted too, arrays keep their order, and whole-number keys come first:

{"b":{"d":1,"c":2},"a":[{"z":0,"y":1}],"10":"x","2":"y"}

{
  "2": "y",
  "10": "x",
  "a": [
    {
      "y": 1,
      "z": 0
    }
  ],
  "b": {
    "c": 2,
    "d": 1
  }
}

Processing runs in your browser

All processing happens inside your browser tab. Our servers are not involved at any point.

Technical specification

JSON syntax is defined in RFC 8259 (IETF, 2017) and ECMA-404. The tool parses with the browser's strict JSON.parse, so comments and trailing commas are errors, and writes the result with JSON.stringify.

Standard: ECMA-404 / RFC 8259
Browser API: Native JSON.parse and JSON.stringify
Indent: 2 or 4 spaces (none when minifying)
Size limit: Browser memory

Related operations

For converting between data formats, try CSV to JSON or the YAML formatter. To decode tokens, use the JWT decoder. For escaping URL data, try URL encode.

Frequently asked questions

Why sort JSON keys?: Sorted keys make it easier to diff two JSON files and to find specific fields quickly.
Does it sort nested objects too?: Yes. Keys are sorted recursively through every level of the object.
Does the order of array items change?: Array order is preserved; only object keys are sorted.
Are uppercase and lowercase keys sorted together?: Sorting uses JavaScript's default string order, which compares UTF-16 code units, so every uppercase ASCII letter (A-Z) comes before every lowercase one (a-z): "Zebra" sorts before "apple". Keys that are whole numbers come first of all, in numeric order.

Last reviewed September 30, 2026

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