head to head · open source
fastapi vs zod-to-openapi
fastapi has 102,409 GitHub stars, 9,906 forks, 78 open issues and last shipped 5 days ago. zod-to-openapi has 1,619 stars, 103 forks, 39 open issues and last shipped 6 days ago. fastapi leads on adoption by 6,225% (102,409 vs 1,619 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 6%. 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 | ★ 102K | ★ 1.6K |
| License | MIT | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-09-14 | 2026-09-13 |
| Forks | ⑂ 9.9K | ⑂ 103 |
| 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 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 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 zod-to-openapi
A TypeScript library from Astea Solutions that generates OpenAPI (Swagger) documentation directly from Zod schemas, for API developers and teams who already validate requests with Zod and do not want to maintain a second, hand written specification.
read the full zod-to-openapi overview →
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Frequently asked questions
Is fastapi or zod-to-openapi more popular?
fastapi has 102,409 GitHub stars and zod-to-openapi has 1,619. 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 (102,409 stars) or its MIT licence terms. Choose zod-to-openapi if its feature set, stack or MIT licence fits better. Both are self-hostable.