Syntax Checker & Code Validator
About FormData → JSON Converter
The FormData to JSON Object Converter parses raw `multipart/form-data` payloads, URL-encoded form submissions, and `FormData.entries()` streams into clean structured JSON objects, automatically reconstructing bracketed nested arrays and numbers.
How to Use FormData → JSON Converter
Step 1
Paste raw FormData key-value pairs or URL-encoded form string.
Step 2
Toggle automatic type conversion and nested bracket parsing.
Step 3
Inspect the structured JSON output.
Step 4
Click "Copy JSON".
Practical Use Cases for FormData → JSON Converter
Parsing Form Submissions in API Handlers
Convert `FormData` objects captured in React/Next.js Server Actions into validated JSON objects for database models.
Debugging Raw Webhook & HTTP Form Payloads
Transform incoming form payloads with bracketed field names (`user[profile][name]`) into clean nested JSON.
Input & Output Examples
Converting FormData Entries to JSON
`username=alice&roles[]=admin&roles[]=user&settings[theme]=dark`
`{\n "username": "alice",\n "roles": ["admin", "user"],\n "settings": { "theme": "dark" }\n}`Key Features & Performance
- ✓Parses bracket notation (`items[]`, `user[name]`, `user[address][city]`) into nested JSON hierarchies.
- ✓Type inference: auto-parses numeric strings (`"123"` $\rightarrow$ `123`) and booleans (`"true"` $\rightarrow$ `true`).
- ✓Generates JavaScript `Object.fromEntries()` and custom parser helper code.
- ✓100% Client-Side memory execution.
- ✓1-Click Copy JSON.
Key Terminology & Definitions
Deep Object Reconstruction
The process of parsing nested key strings (e.g. `a[b][c]=1`) and creating corresponding nested object properties `{a: {b: {c: 1}}}`.
`FormData.entries()`
An iterator returning all key/value pairs contained in a FormData object.