head to head · open source
fastapi vs light-4j
fastapi has 104,566 GitHub stars, 10,179 forks, 78 open issues and last shipped yesterday. light-4j has 3,676 stars, 623 forks, 15 open issues and last shipped yesterday. fastapi leads on adoption by 2,745% (104,566 vs 3,676 stars). fastapi is written in Python under MIT; light-4j is written in Java under Apache-2.0. fastapi has attracted 10% as many forks as stars, light-4j 17%. light-4j was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| fastapi | light-4j | |
|---|---|---|
| GitHub stars | ★ 105K | ★ 3.7K |
| License | MIT | Apache-2.0 |
| Written in | Python | Java |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 10K | ⑂ 623 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick fastapi if
- You weight community size — 105K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick light-4j if
- You want the light-4j feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and light-4j fits your workflow better
About fastapi
FastAPI framework, high performance, easy to learn, fast to code, ready for production Documentation : Source Code : FastAPI is a modern, fast (high performance), web framework for building APIs with Python based on standard Python type hints. The key features are: Fast : Very high performance, on par with NodeJS and Go (thanks to Starlette and Pydantic). One of the fastest Python frameworks available. Fast to code : Increase the speed to develop features by about 200% to 300%. Fewer bugs : Reduce about 40% of human (developer) induced errors. Intuitive : Great editor support. Completion everywhere. Less time…
read the full fastapi overview →
About light-4j
A fast, lightweight and cloud native microservices framework. Stack Overflow Google Group Gitter Chat Subreddit Youtube Channel Documentation Contribution Guide Why call it Light 4J Light means lightweight, lightning fast and shedding light on how to program with modern Java SE for cloud native deployment. Why am I doing it I had been working on the Java EE platforms since early 2000 and suffered the performance and productivity issues. In 2014, I realized that the IT industry was moving from Monolithic to Microservices and from on premise data centers to the public clouds. To reduce the production cost for my…
read the full light-4j overview →
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Frequently asked questions
Is fastapi or light-4j more popular?
fastapi has 104,566 GitHub stars and light-4j has 3,676. fastapi has the larger community by that measure.
Are fastapi and light-4j free?
Both are open source. fastapi is licensed under MIT and light-4j under Apache-2.0. Neither carries a licence fee.
What is the difference between fastapi and light-4j?
fastapi is written in Python and light-4j in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, fastapi or light-4j?
Choose fastapi if you want the larger community (104,566 stars) or its MIT licence terms. Choose light-4j if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.