Object → FormData Generator
Generate JS FormData.append() code snippets from JSON objects.
Syntax Checker & Code Validator
About Object → FormData Generator
The Object to FormData Code Generator converts JSON objects, nested dictionaries, and array lists into executable JavaScript / TypeScript `FormData.append()` statements and reusable serialization helper functions for `multipart/form-data` API requests.
How to Use Object → FormData Generator
Step 1
Paste your JSON payload into the input editor.
Step 2
Select array notation style (Bracket `[]` or Indexed `[0]`).
Step 3
Review the generated `FormData` code.
Step 4
Click "Copy Code".
Practical Use Cases for Object → FormData Generator
Constructing `multipart/form-data` Fetch Requests
Convert frontend form state objects into `FormData` append statements for file upload endpoints and REST APIs.
Handling Nested Arrays in FormData Keys
Format nested objects and arrays with standardized bracket notation (`user[tags][]`, `address[city]`) for backend form parsers.
Input & Output Examples
Converting User Object to FormData Code
`{ "name": "Alice", "tags": ["admin", "staff"] }``const formData = new FormData();\nformData.append("name", "Alice");\nformData.append("tags[]", "admin");\nformData.append("tags[]", "staff");`Key Features & Performance
- ✓Generates vanilla JS / TS `FormData.append()` code snippets.
- ✓Array formatting modes: Bracket syntax (`tags[]`), Index syntax (`tags[0]`), or repeated keys (`tags`).
- ✓Includes ready-to-use recursive `objectToFormData(obj)` helper function.
- ✓100% Client-Side memory execution.
- ✓1-Click Copy code.
Key Terminology & Definitions
`FormData` Interface
A web API object used to compile a set of key/value pairs to send using `fetch()` or `XMLHttpRequest`, encoded as `multipart/form-data`.
Bracket Notation (`tags[]`)
A convention used by PHP, Rails, and Express `qs` to parse multiple form fields into an array on the server.