head to head · open source
fastapi vs swagger-core
fastapi has 104,566 GitHub stars, 10,179 forks, 78 open issues and last shipped yesterday. swagger-core has 7,534 stars, 2,255 forks, 197 open issues and last shipped 6 days ago. fastapi leads on adoption by 1,288% (104,566 vs 7,534 stars). fastapi is written in Python under MIT; swagger-core is written in Java under Apache-2.0. fastapi has attracted 10% as many forks as stars, swagger-core 30%. fastapi was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (openapi, openapi3), so they are genuine substitutes rather than adjacent tools.
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 | swagger-core | |
|---|---|---|
| GitHub stars | ★ 105K | ★ 7.5K |
| License | MIT | Apache-2.0 |
| Written in | Python | Java |
| Last push | 2026-11-02 | 2026-10-28 |
| Forks | ⑂ 10K | ⑂ 2.3K |
| 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 swagger-core if
- You want the swagger-core 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 swagger-core 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 swagger-core
Swagger Core NOTE: If you're looking for Swagger Core 1.5.X and OpenAPI 2.0, please refer to 1.5 branch. NOTE: Since version 2.1.7, Swagger Core also supports the Jakarta namespace. There are a parallel set of artifacts with the jakarta suffix, providing the same functionality as the unsuffixed (i.e.: javax ) artifacts. Please see the Wiki for more details. NOTE: Since version 2.2.0 Swagger Core supports OpenAPI 3.1; see this page for details Swagger Core is a Java implementation of the OpenAPI Specification. Current version supports JAX RS2 ( javax and jakarta namespaces). Get started with Swagger Core! See the…
read the full swagger-core overview →
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Frequently asked questions
Is fastapi or swagger-core more popular?
fastapi has 104,566 GitHub stars and swagger-core has 7,534. fastapi has the larger community by that measure.
Are fastapi and swagger-core free?
Both are open source. fastapi is licensed under MIT and swagger-core under Apache-2.0. Neither carries a licence fee.
What is the difference between fastapi and swagger-core?
fastapi is written in Python and swagger-core 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 swagger-core?
Choose fastapi if you want the larger community (104,566 stars) or its MIT licence terms. Choose swagger-core if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.