JSON to Java POJO: Turn Any JSON into Java Classes

How to use the JSON to Java POJO Converter

1. 1. Paste your JSONUse a sample API response or any JSON object.
2. 2. Choose a stylePick plain getters and setters, Lombok or a Java record.
3. 3. Copy the classesPress Convert and copy or download the .java file.

How types are worked out

The converter reads each value in your JSON and picks a Java type:

• Text becomes String.
• Whole numbers become int, or long if bigger than 2,147,483,647.
• Decimals become double; true/false becomes boolean.
• Nested objects become their own static nested class.
• Arrays become List<T>, with T taken from the items; arrays of objects get a class named in the singular (projects → Project).
• null becomes Object, because the real type cannot be guessed.

Keys that are not valid Java names are converted to camelCase, and an @JsonProperty annotation keeps the original name, so pin_code becomes the field pinCode with @JsonProperty("pin_code").

Worked example

The sample JSON describes an employee with an id, name, active flag, salary, a skills array, an address object and a projects array. Converting it with the root name Employee gives 3 classes and 11 fields:

• Employee: int id, String name, boolean isActive, double salary, List<String> skills, Address address, List<Project> projects (7 fields)
• Address: String city, String pinCode (2 fields)
• Project: String title, int year (2 fields)

Pick Lombok to replace the getters and setters with @Data, which is common in Spring Boot projects. Pick record for Java 16 and later when you want immutable data carriers. Tick wrapper types if a value can be missing, because Integer can hold null and int cannot.

Frequently asked questions