Convert JSON to Form Data
Generate URL-encoded HTTP form data from a JSON object. Runs entirely in your browser, so your data never leaves your device.
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Output
The result appears here as you type.
How to use Convert JSON to Form Data
- 1. Paste your JSON. Paste the JSON object you want to encode as HTTP form data, including any nested objects or arrays that need to become bracketed or dotted keys.
- 2. Choose the nested key style. Pick Brackets a[b] to represent nested keys the way PHP and many web frameworks expect, or Dots a.b for the flatter dot notation some APIs and query-string parsers prefer instead.
- 3. Copy the encoded form data. Copy the resulting URL-encoded string and use it as the body of an application/x-www-form-urlencoded HTTP request, or append it to a URL as query parameters.
When to use Convert JSON to Form Data
Convert JSON to Form Data turns a JSON object into URL-encoded HTTP form data, the application/x-www-form-urlencoded format many older endpoints and traditional HTML forms still expect instead of a JSON request body.
- Submitting to a legacy endpoint that rejects JSON bodies. An older API only accepts application/x-www-form-urlencoded request bodies, but your application's data model is JSON, so this bridges the two before you send the request.
- Testing a form submission with curl. You want to test how a server handles a form POST and need the exact urlencoded body string to include in a curl command, generated from a JSON object you already have.
- Replicating a browser form submission programmatically. You are writing a script to submit an HTML form that a browser would normally serialize automatically, and need the equivalent urlencoded string built from JSON input.
- Debugging how nested fields serialize into form data. You want to confirm whether a nested object turns into bracket notation or dot notation before relying on that behavior in production code.
Examples
Encode a nested object
Input
{"user": {"name": "Ada", "tags": ["a", "b"]}}Output
user%5Bname%5D=Ada&user%5Btags%5D%5B0%5D=a&user%5Btags%5D%5B1%5D=b
About the Convert JSON to Form Data tool
Convert JSON to Form Data is a free online tool that works entirely inside your web browser. Generate URL-encoded HTTP form data from a JSON object. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 90 JSON utilities on EditSafely. Each one does a single job well, and all of them follow the same rule: your input stays on your machine.
You can shape the output with the Nested keys setting, and the result refreshes the moment you change it. A worked example further down the page shows exactly what the tool produces for a real input.
Because nothing leaves your device, the tool is suitable for sensitive content such as internal documents, credentials or customer data. It also responds instantly, since every keystroke is handled on your own machine rather than by a remote API.
Frequently asked questions
Is Convert JSON to Form Data free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.