FASTJSON

Health v2 · maintenance only

Adoption not part of the score

4416 stars · 619 forks observed · 2026-10-07

What it is AI-extracted, prompt v1, taxonomy v1, 2026-10-12, confidence 0.97

Fastjson is a Java library for converting Java objects to JSON and parsing JSON strings back into Java objects. It offers high performance and extensive support for Java generics and complex object structures.

Use cases

• convert Java objects to JSON strings for API responses
• parse incoming JSON payloads into Java objects in a web service
• serialize large data structures for storage or messaging
• handle JSON in Android applications with minimal overhead
• support custom JSON representations for third‑party Java classes

When to choose

• you need the fastest JSON serialization/deserialization on the JVM
• your project runs on Java or Android and requires low‑latency JSON handling
• you need support for complex generic types and deep inheritance hierarchies

When to avoid

• security is a primary concern and you cannot guarantee safe type handling (auto‑type features can be risky)
• you prefer a library with a more modern API surface or built‑in JSON schema validation
• your project targets non‑JVM languages or platforms

Facets

library · maturity active

serialization parser web-development backend jvm fastjson fastjson2 high-performance jvm json data-engineering android

Member repositories

For agents

markdown · JSON · MCP: product_card(name="alibaba/fastjson2")