JSON to Java Class Generator

How it works

How to use the JSON ↔ Java

1. Paste JSON

   Any object or array.

2. Pick a style

   Plain POJO with getters/setters, Lombok @Data, or a Java 16+ record. Add a package name if you like.

3. Map it

   Use Jackson ObjectMapper.readValue(json, Root.class) or Gson.

Type mapping

Fields use camelCase names with @JsonProperty when the JSON key differs. Whole numbers become int/long, decimals double, and values that can be null or missing use boxed types (Integer, Boolean). Arrays become List<T>. Nested objects are emitted as nested static classes so the output compiles as a single file. The reverse mode reads fields, records and annotations (Jackson and Gson) to build sample JSON.

Built for developers

Why developers use it

• Private by design

  Runs 100% in your browser. Nothing you paste is uploaded, logged or stored on a server.

• Instant results

  Output updates as you type, with precise error locations when something is wrong.

• Works offline

  Once loaded, the tool keeps working without a connection. Install it as an app if you like.

• Free, no sign-up

  No accounts, no limits, no watermarks.

FAQ

Frequently asked questions

Keep going

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