JSON to Flow Types
Generate Flow object types from JSON.
Use JSON to Flow Types to skip the boilerplate of hand-writing data models. It's the go-to free choice when you're consuming a JSON API and need matching flow Types fast — paste, copy, done. No sign-up, no install, and your payload never leaves the browser.
About JSON to Flow Types
Building a typed app and tired of hand-writing models? JSON to Flow Types turns a real JSON payload into flow Types in a single paste — it generate Flow object types from JSON. Drop in an API response, copy the generated code, and keep your types in lockstep with the data. Like every ToolJolt utility it runs 100% in your browser — no sign-up, no upload, and nothing ever sent to a server, so it's safe for proprietary code and confidential data.
How to use JSON to Flow Types
- 1Paste a representative JSON payload (an API response works great).
- 2The tool infers the field types and nested structures instantly.
- 3Review the generated code, then copy or download it straight into your project.
- 4Tweak the JSON and re-run any time — it's free and unlimited.
Why use JSON to Flow Types?
- ✓Infers types automatically from a real JSON sample
- ✓Handles nested objects and arrays of objects
- ✓Copy or download the generated types in one click
- ✓Saves the tedious, error-prone work of writing models by hand
Frequently asked questions
How does JSON to Flow Types infer types?+
It walks your JSON sample and maps each value to the closest static type — numbers, strings, booleans, arrays and nested objects each become the idiomatic type for the target language. Provide a complete example for the most accurate result.
Will the generated code compile as-is?+
It's designed to drop straight in, but you should review naming and nullability. JSON can't express every nuance (e.g. unions or optionals), so treat the output as a strong first draft you can refine.
Is JSON to Flow Types free?+
Yes. JSON to Flow Types is completely free with no sign-up, no account, no usage limits and no watermarks. Use it as often as you like.
Does JSON to Flow Types send my data to a server?+
No. JSON to Flow Types runs entirely in your browser with JavaScript — your input never leaves your device, which makes it safe for private API payloads, schemas and source code.
Embed JSON to Flow Types on your website
Want JSON to Flow Typeson your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/json-to-flow" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="JSON to Flow Types — ToolJolt" loading="lazy"></iframe>Related Data tools
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