head to head · open source
fastapi vs openapi-generator-cli
fastapi has 104,566 GitHub stars, 10,179 forks, 78 open issues and last shipped yesterday. openapi-generator-cli has 1,991 stars, 212 forks, 71 open issues and last shipped yesterday. fastapi leads on adoption by 5,152% (104,566 vs 1,991 stars). fastapi is written in Python under MIT; openapi-generator-cli is written in TypeScript under Apache-2.0. fastapi has attracted 10% as many forks as stars, openapi-generator-cli 11%. 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 | openapi-generator-cli | |
|---|---|---|
| GitHub stars | ★ 105K | ★ 2.0K |
| License | MIT | Apache-2.0 |
| Written in | Python | TypeScript |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 10K | ⑂ 212 |
| 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 openapi-generator-cli if
- You want the openapi-generator-cli feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and openapi-generator-cli 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 openapi-generator-cli
@openapitools/openapi generator cli OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (both 2.0 and 3.0 are supported). Please see OpenAPITools/openapi generator. The OpenAPI Generator is a Java project. openapi generator cli will download the appropriate JAR file and invoke the java executable to run the OpenAPI Generator. You must have the java binary executable available on your PATH for this to work. (JDK 11 is the minimal version supported. To install OpenJDK, please visit If you find this tool…
read the full openapi-generator-cli overview →
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Frequently asked questions
Is fastapi or openapi-generator-cli more popular?
fastapi has 104,566 GitHub stars and openapi-generator-cli has 1,991. fastapi has the larger community by that measure.
Are fastapi and openapi-generator-cli free?
Both are open source. fastapi is licensed under MIT and openapi-generator-cli under Apache-2.0. Neither carries a licence fee.
What is the difference between fastapi and openapi-generator-cli?
fastapi is written in Python and openapi-generator-cli in TypeScript. 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 openapi-generator-cli?
Choose fastapi if you want the larger community (104,566 stars) or its MIT licence terms. Choose openapi-generator-cli if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.