head to head · open source
openapi-generator vs grpc-gateway
openapi-generator has 26,846 GitHub stars, 7,748 forks, 5,819 open issues and last shipped yesterday. grpc-gateway has 20,012 stars, 2,415 forks, 149 open issues and last shipped yesterday. openapi-generator leads on adoption by 34% (26,846 vs 20,012 stars). openapi-generator is written in Java under Apache-2.0; grpc-gateway is written in Go under BSD-3-Clause. openapi-generator has attracted 29% as many forks as stars, grpc-gateway 12%. grpc-gateway was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (openapi, rest-api, restful-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
| openapi-generator | grpc-gateway | |
|---|---|---|
| GitHub stars | ★ 27K | ★ 20K |
| License | Apache-2.0 | BSD-3-Clause |
| Written in | Java | Go |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 7.7K | ⑂ 2.4K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick openapi-generator if
- You weight community size — 27K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick grpc-gateway if
- You want the grpc-gateway feature set and don't need the biggest community
- You prefer the BSD-3-Clause license terms
- Your stack matches Go
- You evaluated both and grpc-gateway fits your workflow better
About openapi-generator
OpenAPI Generator Master ( 7.27.0 ): :star::star::star: If you would like to contribute, please refer to guidelines and a list of open tasks. :star::star::star: :bangbang: To migrate from Swagger Codegen to OpenAPI Generator, please refer to the migration guide :bangbang: :notebook with decorative cover: For more information, please refer to the Wiki page and FAQ :notebook with decorative cover: :notebook with decorative cover: The eBook A Beginner's Guide to Code Generation for REST APIs is a good starting point for beginners :notebook with decorative cover: :warning: If the OpenAPI spec, templates or any input…
read the full openapi-generator overview →
About grpc-gateway
gRPC Gateway gRPC to JSON proxy generator following the gRPC HTTP spec About The gRPC Gateway is a plugin of the Google protocol buffers compiler protoc. It reads protobuf service definitions and generates a reverse proxy server which translates a RESTful HTTP API into gRPC. This server is generated according to the google.api.http annotations in your service definitions. This helps you provide your APIs in both gRPC and RESTful style at the same time. Docs You can read our docs at: Testimonials We use the gRPC Gateway to serve millions of API requests per day, and have been since 2018 and through all of that…
read the full grpc-gateway overview →
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Frequently asked questions
Is openapi-generator or grpc-gateway more popular?
openapi-generator has 26,846 GitHub stars and grpc-gateway has 20,012. openapi-generator has the larger community by that measure.
Are openapi-generator and grpc-gateway free?
Both are open source. openapi-generator is licensed under Apache-2.0 and grpc-gateway under BSD-3-Clause. Neither carries a licence fee.
What is the difference between openapi-generator and grpc-gateway?
openapi-generator is written in Java and grpc-gateway in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, openapi-generator or grpc-gateway?
Choose openapi-generator if you want the larger community (26,846 stars) or its Apache-2.0 licence terms. Choose grpc-gateway if its feature set, stack or BSD-3-Clause licence fits better. Both are self-hostable.