JSON Parser

Parse any JSON string and instantly see its structure: root type, total key count across all nesting levels, maximum depth, and a fully pretty-printed representation.

Parsed Output

{ "user": { "id": 42, "name": "Alice", "roles": [ "admin", "editor" ] }, "active": true, "score": 98.5 }

Root Type

Object

Root Keys / Items

Total Keys (all levels)

Max Nesting Depth

Parsed Output

{
  "user": {
    "id": 42,
    "name": "Alice",
    "roles": [
      "admin",
      "editor"
    ]
  },
  "active": true,
  "score": 98.5
}

How It Works

Formula

JSON.parse(jsonString)

Worked Example

'{"user":{"id":1,"roles":["admin"]}}' parses to root type Object with 3 total keys and nesting depth 2.

Understanding JSON Structure

JSON has six data types: string, number, boolean, null, object, and array. Objects are unordered key-value maps; arrays are ordered sequences. This parser reports:

Root Type — whether the top-level value is an object, array, string, number, or other primitive.
Root Keys / Items — number of direct children of the root container.
Total Keys — all keys across every nesting level, giving a sense of total payload complexity.
Max Nesting Depth — how deeply nested the structure is (relevant for recursive algorithms and stack limits).

Frequently Asked Questions

What does a JSON parser do?

A JSON parser reads a JSON-encoded string and converts it into native data structures (objects, arrays, strings, numbers, booleans, null) that a program can inspect and manipulate.

What is JSON nesting depth?

Nesting depth is the maximum number of container levels (objects or arrays) from the root to the deepest leaf value. A flat object has depth 1; each additional nested object increases depth by 1.

Why does my JSON fail to parse?

Common causes: trailing commas after the last element, single quotes instead of double quotes, unquoted keys, JavaScript comments, or undefined/NaN values — none of which are valid in standard JSON (RFC 8259).

Is my data safe when using this parser?

Yes. All parsing happens 100% client-side in your browser using the native JSON.parse() API. No data is sent to any server.

Sources: