head to head · open source
fastapi vs light-4j
fastapi has 102,409 GitHub stars, 9,906 forks, 78 open issues and last shipped 4 days ago. light-4j has 3,672 stars, 625 forks, 15 open issues and last shipped yesterday. fastapi leads on adoption by 2,689% (102,409 vs 3,672 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 | ★ 102K | ★ 3.7K |
| License | MIT | Apache-2.0 |
| Written in | Python | Java |
| Last push | 2026-09-14 | 2026-09-17 |
| Forks | ⑂ 9.9K | ⑂ 625 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick fastapi if
- You weight community size — 102K 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 is an MIT licensed, high performance Python web framework for building APIs with standard Python type hints, aimed at Python developers and teams that need production ready HTTP services with automatic OpenAPI documentation.
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 ap…
read the full light-4j overview →
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Frequently asked questions
Is fastapi or light-4j more popular?
fastapi has 102,409 GitHub stars and light-4j has 3,672. 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 (102,409 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.