JSON To TypeScript Generator
JSON to TypeScript
Paste input, adjust settings if needed, then run.
Infer TypeScript declarations from JSON payloads, including optional fields and union values.
Result size
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Output summary
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Input: manualFile input
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Settings
Status
Waiting for output.
Health 55/100
JSON to TypeScript policy
Type inference is sample-driven and may need manual hardening for production contracts.
Inference basis
MEDIUM riskGenerated interfaces are inferred only from the provided sample payload.
Optional and union handling
MEDIUM riskMissing keys across sample objects become optional and mixed values become union types.
Runtime contract risk
HIGH riskIf production payloads include unseen shapes, generated types can be incomplete until samples are expanded.
Result sizeLive
0chars
Run to update output.
Copy result = output only. Copy report = output + settings.
Privacy note
Flow
- Parse JSON sample into structured values.
- Infer field types across objects and arrays, including optional keys when fields are missing in some samples.
- Emit TypeScript interfaces/types with deterministic naming rules.
Example
Worked example: user payload inference
- 1 Input includes two payload items where some keys exist only in one sample.
- 2 Inference maps primitives, array element types, and marks missing keys as optional.
- 3 Output produces declarations with optional fields and union-safe typing where values vary.
Generated interfaces remove manual type-writing for common payloads.
How
- Paste representative JSON into the input panel.
- Run type inference and inspect generated interfaces.
- Copy the generated TypeScript into your project.
Cases
- Bootstrap front-end API clients from real response samples.
- Create quick schema contracts for internal tooling.
- Align back-end and front-end teams on payload shape.
Avoid
- Using incomplete sample payloads that hide optional fields.
- Treating inferred output as a full runtime validator.
- Ignoring naming cleanup for autogenerated type identifiers.
FAQ
Does json to typescript generator send my input to a server?
No. JSON To TypeScript Generator handles the input in your browser whenever possible, so routine conversions, previews, and copy actions stay on your device instead of being sent to Calctrove servers.
Can this infer optional fields?
Yes. When a field exists in some objects but not others, the generated declaration marks it as optional.
Should I still review generated interfaces?
Yes. Use generated types as a starting point, then refine names and optional fields for production code.
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