JS to JSON Converter

A VS Code extension that converts JavaScript object literals into valid JSON with a single command.

What it does

Turns this:

{
    name: 'John',
    age: 30,
    active: true,
    address: {
        city: 'Berlin',
        zip: '10115',
    },
    tags: ['admin', 'user'],
}

Into this:

{
  "name": "John",
  "age": 30,
  "active": true,
  "address": {
    "city": "Berlin",
    "zip": "10115"
  },
  "tags": [
    "admin",
    "user"
  ]
}

Specifically it handles:

• Unquoted keys → "quoted keys"
• Single-quoted strings → "double-quoted strings"
• Trailing commas (on objects and arrays)
• Nested objects and arrays
• Numbers, booleans, null

Note: Values that have no JSON equivalent — functions, undefined, class instances — cannot be converted and will show an error.

Usage

Option 1 — Convert a selection

1. Select the JS object text in the editor
2. Use any of the triggers below — the selection is replaced with valid JSON

Option 2 — Convert the entire file

1. Make sure nothing is selected
2. Use any of the triggers below — the entire file contents are replaced with valid JSON

Triggers

Examples

Simple object

Input (selected):

{ id: 1, status: 'active' }

Output:

{
  "id": 1,
  "status": "active"
}

Nested object with trailing commas

Input (selected):

{
    user: {
        name: 'Alice',
        roles: ['admin', 'editor',],
    },
}

Output:

{
  "user": {
    "name": "Alice",
    "roles": [
      "admin",
      "editor"
    ]
  }
}

Array of objects

Input (selected):

[
    { id: 1, label: 'First' },
    { id: 2, label: 'Second' },
]

Output:

[
  { "id": 1, "label": "First" },
  { "id": 2, "label": "Second" }
]

Error cases

If the selection cannot be parsed as a JS object, an error message appears at the bottom of the screen explaining what went wrong. The editor content is not modified.

Common reasons for failure:

• The text contains a function value: { fn: () => {} }
• The text is not a valid JS expression at all
• The text contains undefined values

Installation

From the Marketplace

Search for JS to JSON Converter in the VS Code Extensions panel (Cmd+Shift+X) and click Install.

From a .vsix file

code --install-extension js-to-json-0.0.1.vsix

Or via VS Code: Extensions panel → ... menu (top-right) → Install from VSIX...