JSON to Java Converter

Convert your JSON data to Java classes with our powerful online tool. Features include nested JSON support, custom class names, and real-time preview.

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What is a JSON to Java Converter?

Paste a JSON sample here to generate the matching Java POJO classes (fields, getters, setters, nested types) ready for Jackson or Gson to bind against.

A JSON to Java converter walks the JSON structure, infers each field type, and emits idiomatic Java classes, so you skip the boilerplate every time a new endpoint shows up.

This tool handles nested objects, custom root class names, and standard getter/setter patterns, which makes the output drop-in for Spring, Android, or plain Java backend projects.

How to Use Our JSON to Java Converter

Paste your JSON data into the left editor or click the sample data button to load example JSON
Enter your desired root class name in the class name input field
The tool validates your JSON and highlights any syntax errors immediately
The converter generates Java POJO classes with private fields, getters, and setters in real-time
Nested JSON objects are automatically converted into separate inner or referenced Java classes
Copy the generated Java code to clipboard or download it as a .java file

Examples

Configuration JSON to POJO with getters

A service configuration sample becomes a POJO with private fields plus getter/setter pairs — drop it into a Spring @ConfigurationProperties class.

Input

{
  "host": "db.internal",
  "port": 5432,
  "useSsl": true
}

Output

public class DbConfig {
    private String host;
    private int port;
    private boolean useSsl;

    public String getHost() { return host; }
    public void setHost(String host) { this.host = host; }

    public int getPort() { return port; }
    public void setPort(int port) { this.port = port; }

    public boolean isUseSsl() { return useSsl; }
    public void setUseSsl(boolean useSsl) { this.useSsl = useSsl; }
}

Nested API response with list field

Arrays map to List<T> and nested objects become separate classes — Jackson and Gson can deserialize both without extra annotations.

Input

{
  "id": 7,
  "title": "Welcome",
  "tags": ["intro", "onboarding"]
}

Output

import java.util.List;

public class Article {
    private int id;
    private String title;
    private List<String> tags;

    public int getId() { return id; }
    public void setId(int id) { this.id = id; }

    public String getTitle() { return title; }
    public void setTitle(String title) { this.title = title; }

    public List<String> getTags() { return tags; }
    public void setTags(List<String> tags) { this.tags = tags; }
}

JSON specification reference

Quick reference from RFC 8259. The converter enforces these rules on input; anything outside them is rejected or normalized.

Element	Meaning	Example
Object	Unordered set of key/value pairs	{"a": 1}
Array	Ordered list of values	[1, 2, "x"]
String	Unicode, double-quoted only	"hello"
Number	IEEE 754 double, no NaN / Infinity	3.14
Literal	true / false / null only	null

Common invalid forms

{'a': 1}  // single quotes not allowed
{a: 1}    // unquoted keys
{"a": 1,} // trailing comma
NaN       // not permitted by RFC 8259

Key Features

POJO Generation: Creates complete Java classes with private fields, public getters/setters, and proper encapsulation
Smart Type Inference:Automatically maps JSON types to Java types — strings to String, numbers to int/double, arrays to List<T>
Nested Class Support: Nested JSON objects generate separate Java classes with proper references and imports
Java Naming Conventions: Follows camelCase for fields and PascalCase for class names, producing idiomatic Java code
100% Client-Side: All code generation happens in your browser — your data never leaves your device, ensuring complete privacy

Frequently Asked Questions

Q: How does the converter infer Java types from JSON values?

The converter analyzes each JSON value to determine the most appropriate Java type. Integers map to int, floating-point numbers to double, booleans to boolean, strings to String, and arrays to List<T> where T is inferred from the array elements. Nested objects generate separate Java classes with properly typed references.

Q: Does the converter generate getters and setters?

Yes. The converter generates Java POJO classes with private fields and public getter and setter methods following standard Java naming conventions. This produces ready-to-use classes that follow Java best practices for encapsulation.

Q: How does the converter handle nested objects and arrays in Java?

Nested JSON objects are converted into separate Java classes with proper references. Arrays are mapped to List<T> types where T is the inferred element type. This produces a complete set of classes that accurately represent the full JSON structure.

Q: Are there any file size limitations?

There is no hard file size limit. Since all processing happens in your browser, the practical limit depends on your device's available memory. Most modern browsers can handle JSON files up to several megabytes without issues.

Q: Are the generated classes compatible with Jackson and Gson?

Yes. The generated Java classes use standard POJO conventions with getters and setters, making them fully compatible with popular JSON libraries like Jackson, Gson, and Moshi for serialization and deserialization without any modifications.

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JSON to Java Converter

Convert your JSON data to Java classes with our powerful online tool. Features include nested JSON support, custom class names, and real-time preview.

Loading editors...

Auto Sync

Automatically sync from left

Loading editors...

What is a JSON to Java Converter?

Paste a JSON sample here to generate the matching Java POJO classes (fields, getters, setters, nested types) ready for Jackson or Gson to bind against.

A JSON to Java converter walks the JSON structure, infers each field type, and emits idiomatic Java classes, so you skip the boilerplate every time a new endpoint shows up.

This tool handles nested objects, custom root class names, and standard getter/setter patterns, which makes the output drop-in for Spring, Android, or plain Java backend projects.

How to Use Our JSON to Java Converter

Paste your JSON data into the left editor or click the sample data button to load example JSON
Enter your desired root class name in the class name input field
The tool validates your JSON and highlights any syntax errors immediately
The converter generates Java POJO classes with private fields, getters, and setters in real-time
Nested JSON objects are automatically converted into separate inner or referenced Java classes
Copy the generated Java code to clipboard or download it as a .java file

Examples

Configuration JSON to POJO with getters

A service configuration sample becomes a POJO with private fields plus getter/setter pairs — drop it into a Spring @ConfigurationProperties class.

Input

{
  "host": "db.internal",
  "port": 5432,
  "useSsl": true
}

Output

public class DbConfig {
    private String host;
    private int port;
    private boolean useSsl;

    public String getHost() { return host; }
    public void setHost(String host) { this.host = host; }

    public int getPort() { return port; }
    public void setPort(int port) { this.port = port; }

    public boolean isUseSsl() { return useSsl; }
    public void setUseSsl(boolean useSsl) { this.useSsl = useSsl; }
}

Nested API response with list field

Arrays map to List<T> and nested objects become separate classes — Jackson and Gson can deserialize both without extra annotations.

Input

{
  "id": 7,
  "title": "Welcome",
  "tags": ["intro", "onboarding"]
}

Output

import java.util.List;

public class Article {
    private int id;
    private String title;
    private List<String> tags;

    public int getId() { return id; }
    public void setId(int id) { this.id = id; }

    public String getTitle() { return title; }
    public void setTitle(String title) { this.title = title; }

    public List<String> getTags() { return tags; }
    public void setTags(List<String> tags) { this.tags = tags; }
}

JSON specification reference

Quick reference from RFC 8259. The converter enforces these rules on input; anything outside them is rejected or normalized.

Element	Meaning	Example
Object	Unordered set of key/value pairs	{"a": 1}
Array	Ordered list of values	[1, 2, "x"]
String	Unicode, double-quoted only	"hello"
Number	IEEE 754 double, no NaN / Infinity	3.14
Literal	true / false / null only	null

Common invalid forms

{'a': 1}  // single quotes not allowed
{a: 1}    // unquoted keys
{"a": 1,} // trailing comma
NaN       // not permitted by RFC 8259

Key Features

POJO Generation: Creates complete Java classes with private fields, public getters/setters, and proper encapsulation
Smart Type Inference:Automatically maps JSON types to Java types — strings to String, numbers to int/double, arrays to List<T>
Nested Class Support: Nested JSON objects generate separate Java classes with proper references and imports
Java Naming Conventions: Follows camelCase for fields and PascalCase for class names, producing idiomatic Java code
100% Client-Side: All code generation happens in your browser — your data never leaves your device, ensuring complete privacy