head to head · open source
fastapi vs just-api
fastapi has 104,566 GitHub stars, 10,179 forks, 78 open issues and last shipped yesterday. just-api has 815 stars, 36 forks, 19 open issues and last shipped 9 months ago. fastapi leads on adoption by 12,730% (104,566 vs 815 stars). fastapi is written in Python under MIT; just-api is written in JavaScript under MIT. fastapi has attracted 10% as many forks as stars, just-api 4%. fastapi was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (api), 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 | just-api | |
|---|---|---|
| GitHub stars | ★ 105K | ★ 815 |
| License | MIT | MIT |
| Written in | Python | JavaScript |
| Last push | 2026-11-02 | 2026-02-12 |
| Forks | ⑂ 10K | ⑂ 36 |
| 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 just-api if
- You want the just-api feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches JavaScript
- You evaluated both and just-api 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 just-api
Just API Just API is a declarative, specification based test framework for REST , GraphQL APIs. Users can test APIs without writing code, but they can also tap into code when they want to. It reads API test specification from YAML files and runs them in serial/parallel mode. Test reports can be generated in several formats including HTML and JSON. In simple terms, users build a test suite by providing a set of request and response validation specification in a YAML file. Each suite can have one or more specs. Just API builds the request, sends it to server and validates response as per the specification. One can…
read the full just-api overview →
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Frequently asked questions
Is fastapi or just-api more popular?
fastapi has 104,566 GitHub stars and just-api has 815. fastapi has the larger community by that measure.
Are fastapi and just-api free?
Both are open source. fastapi is licensed under MIT and just-api under MIT. Neither carries a licence fee.
What is the difference between fastapi and just-api?
fastapi is written in Python and just-api in JavaScript. 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 just-api?
Choose fastapi if you want the larger community (104,566 stars) or its MIT licence terms. Choose just-api if its feature set, stack or MIT licence fits better. Both are self-hostable.