alibaba/fastjson

FASTJSON 2.0.x has been released, faster and more secure, recommend you upgrade.

25,592

stars

3,783

commits

Java

primary language

Jul 29, 2026

updated

github.com/alibaba/fastjson2/wiki/fastjson_1_upgrade_cn
android
best-performance
deserialization
fastjson
java
json
json-parser
json-serialization
json-serializer
serialization
Browse cluster: JSON serialization and parsing libraries

README

fastjson

Java CI Codecov Maven Central GitHub release License Gitpod Ready-to-Code Fuzzing Status QualityGate

Fastjson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Fastjson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of.

FASTJSON 2.0.x has been released, faster and more secure, we recommend you upgrade to the latest version.

Fastjson Goals

  • Provide the best performance on the server-side and android client
  • Provide simple toJSONString() and parseObject() methods to convert Java objects to JSON and vice-versa
  • Allow pre-existing unmodifiable objects to be converted to and from JSON
  • Extensive support of Java Generics
  • Allow custom representations for objects
  • Support arbitrarily complex objects (with deep inheritance hierarchies and extensive use of generic types)

fastjson

Documentation

Benchmark

Download

Maven

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>2.0.31</version>
</dependency>

Gradle via JCenter

compile 'com.alibaba:fastjson:2.0.28'

Please see this Wiki Download Page for more repository info.

License

Fastjson is released under the Apache 2.0 license.

Copyright 1999-2020 Alibaba Group Holding Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at the following link.

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Contributors

(top 30 of 168)

wenshao

3,050 commits

VictorZeng

151 commits

Omega-Ariston

76 commits

kimmking

70 commits

alibaba/fastjson

FASTJSON 2.0.x has been released, faster and more secure, recommend you upgrade.

25,592

stars

3,783

commits

Java

primary language

Jul 29, 2026

updated

github.com/alibaba/fastjson2/wiki/fastjson_1_upgrade_cn
android
best-performance
deserialization
fastjson
java
json
json-parser
json-serialization
json-serializer
serialization
Browse cluster: JSON serialization and parsing libraries

README

fastjson

Java CI Codecov Maven Central GitHub release License Gitpod Ready-to-Code Fuzzing Status QualityGate

Fastjson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Fastjson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of.

FASTJSON 2.0.x has been released, faster and more secure, we recommend you upgrade to the latest version.

Fastjson Goals

  • Provide the best performance on the server-side and android client
  • Provide simple toJSONString() and parseObject() methods to convert Java objects to JSON and vice-versa
  • Allow pre-existing unmodifiable objects to be converted to and from JSON
  • Extensive support of Java Generics
  • Allow custom representations for objects
  • Support arbitrarily complex objects (with deep inheritance hierarchies and extensive use of generic types)

fastjson

Documentation

Benchmark

Download

Maven

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>2.0.31</version>
</dependency>

Gradle via JCenter

compile 'com.alibaba:fastjson:2.0.28'

Please see this Wiki Download Page for more repository info.

License

Fastjson is released under the Apache 2.0 license.

Copyright 1999-2020 Alibaba Group Holding Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at the following link.

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Contributors

(top 30 of 168)

wenshao

3,050 commits

VictorZeng

151 commits

Omega-Ariston

76 commits

kimmking

70 commits

Languages

Java

99.9%