JSON to TypeScript Interface
Generate TypeScript interfaces or a Root type alias from JSON. Every array element contributes to the inferred union; quoted property names and unique interface names preserve unusual keys and avoid collisions.
About this json to typescript interface
Convert JSON sample responses into strictly typed TypeScript interfaces and type aliases.
How this tool works
Generate TypeScript interfaces or a Root type alias from JSON. Every array element contributes to the inferred union; quoted property names and unique interface names preserve unusual keys and avoid collisions.
- Paste one complete JSON value or load the sample.
- Run locally to generate code, then copy the complete result.
- Compile or validate the code in your target project and review inferred types before use.
Worked example
Scenario: TypeScript: Generate a model for the displayed object and retain every original property.
Sample input:
Processing: Infer each value, emit the target declarations, then validate the original object using the target compiler or library.
Illustrative output:
Limits and verification
Accepts JSON text up to 1,000,000 UTF-16 code units and 100 nesting levels; output is limited to 8,388,608 code units. Invalid syntax, duplicate keys, invalid Unicode, unsafe integer values, overflow, underflow and decimal precision loss are rejected. Quote exact large numbers as strings. Dates remain strings. Inference describes the supplied sample, not every possible API response. Use Root with TypeScript strict mode. These declarations do not validate data at runtime or infer optional fields, enums or date types. Empty arrays use unknown elements; an empty interface is broad and is not an exact empty-object validator.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
- ECMA-404 (The JSON Data Interchange Standard)
- TypeScript Language Specification (Interfaces and Type System)
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Paste one complete JSON value or load the sample.
- Run locally to generate code, then copy the complete result.
- Compile or validate the code in your target project and review inferred types before use.
Frequently asked questions
What exact TypeScript interface does this page emit from the sample?+
The sample shape is emitted as export interface Root; arrays and nested objects are inferred from the supplied JSON.
How are JSON names and value types represented in this TypeScript interface?+
Quoted JSON property names and number, string, boolean fields. The sample shape is emitted as export interface Root; arrays and nested objects are inferred from the supplied JSON.
What inference boundary applies to TypeScript interface output?+
It is a sample-derived declaration, not a complete domain schema; invalid JSON, duplicate keys, unsafe numeric values and limits are rejected before generation.
Does TypeScript interface generation execute or upload the generated language?+
Generation runs locally in the browser as text transformation; it does not execute, compile, or upload the generated TypeScript interface. Ordinary page resource requests remain separate.