head to head · open source
fastapi vs zod-to-openapi
fastapi has 104,566 GitHub stars, 10,179 forks, 78 open issues and last shipped yesterday. zod-to-openapi has 1,635 stars, 107 forks, 39 open issues and last shipped 1 months ago. fastapi leads on adoption by 6,295% (104,566 vs 1,635 stars). fastapi is written in Python under MIT; zod-to-openapi is written in TypeScript under MIT. fastapi has attracted 10% as many forks as stars, zod-to-openapi 7%. 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 | zod-to-openapi | |
|---|---|---|
| GitHub stars | ★ 105K | ★ 1.6K |
| License | MIT | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-11-02 | 2026-10-02 |
| Forks | ⑂ 10K | ⑂ 107 |
| 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 zod-to-openapi if
- You want the zod-to-openapi feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and zod-to-openapi 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 zod-to-openapi
Zod to OpenAPI [!IMPORTANT] For Zod v3 support, please use the v7.3.4 version. However keep in mind that we do not intend to actively support that version going forward Install with: npm install @asteasolutions/zod to openapi@7.3.4 A library that uses zod schemas to generate an Open API Swagger documentation. 1. Purpose and quick example 2. Usage 1. Installation 2. The openapi method 3. The Registry 4. The Generator 5. Defining schemas 6. Defining routes & webhooks 7. Defining custom components 8. A full example 9. Adding it as part of your build 10. Using schemas vs a registry 11. Generation options 3. Zod…
read the full zod-to-openapi overview →
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Frequently asked questions
Is fastapi or zod-to-openapi more popular?
fastapi has 104,566 GitHub stars and zod-to-openapi has 1,635. fastapi has the larger community by that measure.
Are fastapi and zod-to-openapi free?
Both are open source. fastapi is licensed under MIT and zod-to-openapi under MIT. Neither carries a licence fee.
What is the difference between fastapi and zod-to-openapi?
fastapi is written in Python and zod-to-openapi 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 zod-to-openapi?
Choose fastapi if you want the larger community (104,566 stars) or its MIT licence terms. Choose zod-to-openapi if its feature set, stack or MIT licence fits better. Both are self-hostable.