Free JSON to Flow

JSON to Flow (2026) ✨

Generate Flow type definitions from JSON. Free, in-browser, no signup. By Folioify.

Fast- convert in seconds

Private- local processing

No Signup- free forever

JSON to Flow Tool 🧰

Paste your input below and the output will update automatically.

TL;DR ⚡

Use JSON to Flow when maintaining a Flow-based codebase and you need a quick type draft from sample API or config data.

Example Input

{
  "id": "prod_1",
  "price": 29,
  "tags": ["tool", "preview"]
}

Expected Output

type Root = {
  id: string,
  price: number,
  tags: Array<string>
};

Core Information 📌

Pricing

Free — no registration required.

Data Handling

Client-side only — runs in your browser.

Output

Instant conversion with clean results.

Target Users

Developers, designers, and creators.

What is JSON to Flow? 🧭

JSON to Flow inspects a JSON sample and generates Flow type definitions that describe the same object shape.

What can it do? ✅

Infer object, array, string, number, boolean, and null shapes.
Generate nested Flow type structures.
Create starting points for API response and config typing.
Help with Flow-to-TypeScript migration audits by making data shapes explicit.

How JSON to Flow works (Step-by-Step) 🪄

Step 1: Paste representative JSON data.
Step 2: The converter infers the shape of the sample.
Step 3: Copy the Flow output and refine names or optional fields.

Common Errors

Invalid JSON input will not parse.
A single sample cannot show fields that are optional in real API responses.
Mixed arrays may infer broader types than expected.

Limitations

Generated types should be reviewed by a developer.
Runtime validation is not generated.
Flow syntax choices may need adjustment for local style rules.

Free vs Paid 💸

This tool is 100% free with no usage limits or account required. You can use it for quick conversions without subscriptions or payments.

Official vs Third-Party 🧪

Folioify provides this as a third-party utility. It does not replace official tools, but offers a fast, accessible alternative for everyday workflows.

Use Cases 💡

Type API examples in an existing Flow project.
Document JSON structures before migration.
Create Flow types for fixtures and test data.

Frequently Asked Questions ❓

Is JSON to Flow useful for new projects?

Most new projects use TypeScript, but this tool is useful for existing Flow codebases and migrations.

Can it infer exact object types?

It creates a practical starting point. Review exactness and optionality based on your Flow configuration.

Can I convert the result to TypeScript?

For migration work, use this to understand the shape, then use Flow-to-TypeScript tooling where needed.

Data Sources & Disclaimer 📎

This tool is provided for educational and productivity purposes. Output accuracy depends on input quality. It relies on well-known open-source libraries where applicable.

Last updated: July 4, 2026. This page is maintained regularly so tool details, examples, and FAQs stay current for developers and AI search systems.