head to head · open source
OpenAPI-Specification vs grpc-gateway
OpenAPI-Specification has 31,291 GitHub stars, 9,145 forks, 80 open issues and last shipped 12 days ago. grpc-gateway has 20,012 stars, 2,415 forks, 149 open issues and last shipped yesterday. OpenAPI-Specification leads on adoption by 56% (31,291 vs 20,012 stars). OpenAPI-Specification is written in Markdown under Apache-2.0; grpc-gateway is written in Go under BSD-3-Clause. OpenAPI-Specification 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 1 topic tag (openapi), 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-Specification | grpc-gateway | |
|---|---|---|
| GitHub stars | ★ 31K | ★ 20K |
| License | Apache-2.0 | BSD-3-Clause |
| Written in | Markdown | Go |
| Last push | 2026-10-22 | 2026-11-02 |
| Forks | ⑂ 9.1K | ⑂ 2.4K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick OpenAPI-Specification if
- You weight community size — 31K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Markdown
- 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-Specification
The OpenAPI Specification The OpenAPI Specification is a community driven open specification within the OpenAPI Initiative, a Linux Foundation Collaborative Project. The OpenAPI Specification (OAS) defines a standard, programming language agnostic interface description for HTTP APIs. This allows both humans and computers to discover and understand the capabilities of a service without requiring access to source code, additional documentation, or inspection of network traffic. When properly defined via OpenAPI, a consumer can understand and interact with the remote service with a minimal amount of implementation…
read the full OpenAPI-Specification 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-Specification or grpc-gateway more popular?
OpenAPI-Specification has 31,291 GitHub stars and grpc-gateway has 20,012. OpenAPI-Specification has the larger community by that measure.
Are OpenAPI-Specification and grpc-gateway free?
Both are open source. OpenAPI-Specification is licensed under Apache-2.0 and grpc-gateway under BSD-3-Clause. Neither carries a licence fee.
What is the difference between OpenAPI-Specification and grpc-gateway?
OpenAPI-Specification is written in Markdown 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-Specification or grpc-gateway?
Choose OpenAPI-Specification if you want the larger community (31,291 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.