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REST APIvsgRPC
What is the difference between REST and gRPC?
Updated 2 min read7 differences
In short
REST exposes resources over HTTP, usually as JSON, while gRPC calls typed remote functions with binary messages over HTTP/2: faster, but harder from browsers.
REST API
Representational State Transfer API
A REST API is a web API that exposes data as resources identified by URLs and lets clients read or change them using standard HTTP methods.
Read the page on REST APIgRPC
gRPC is an open-source framework for calling functions on a remote server as if they were local, using Protocol Buffers and HTTP/2 for fast, typed messages.
Read the page on gRPCREST API and gRPC compared
| Aspect | REST API | gRPC |
|---|---|---|
| Style | Resources at URLs, acted on with HTTP methods | Remote functions called on a typed service |
| Contract | Optional, often documented with OpenAPI | Required .proto file that generates client and server code |
| Payload format | Usually JSON text, easy for humans to read | Protocol Buffers binary, smaller and faster to parse |
| Transport | Any HTTP version: HTTP/1.1, HTTP/2 or HTTP/3 | HTTP/2, with many calls sharing one connection |
| Streaming | Request-response; streaming needs extra techniques | Built-in client, server and bidirectional streaming |
| Browser support | Works natively in every browser | Needs gRPC-Web or a gateway in between |
| Best for | Public APIs, web frontends and simple integrations | Fast, high-volume internal service-to-service calls |
The difference, explained
REST is an architectural style in which clients read and change resources at URLs using HTTP methods, usually exchanging JSON. gRPC is a remote procedure call (RPC) framework, originally created at Google, in which you define services and messages in a .proto file and generate client and server code from it, so calling a remote service looks like calling a local function.
The difference comes from their goals. REST favors simplicity and reach: any HTTP client, browser or command-line tool can call it, and responses are human-readable. gRPC favors efficiency and strict contracts: Protocol Buffers are a compact binary format, HTTP/2 lets many calls share one connection, and streaming in both directions is built in.
Many systems use both. A common pattern is REST or GraphQL at the edge for browsers and third parties, and gRPC between internal microservices, where speed and typed contracts matter most. Gateways can also translate REST calls into gRPC so one service can serve both kinds of clients.
A common misconception is that gRPC is simply a better REST. Browsers cannot call native gRPC directly and need a translation layer such as gRPC-Web, binary messages are harder to inspect while debugging, and for many public APIs the reach and simplicity of REST matter more than raw speed.
Which one should you use?
Choose REST API when…
- Your API is public or called directly from browsers.
- You want responses that people can read and debug with standard tools.
- You rely on HTTP caching, CDNs or easy third-party integrations.
Choose gRPC when…
- Internal services make many calls to each other and latency matters.
- You want strict, generated contracts shared across several languages.
- You need streaming in one or both directions.
- Bandwidth is limited, as on mobile or IoT connections.
Readers ask
Is gRPC faster than REST?
Usually, for service-to-service calls, because binary Protocol Buffers are smaller than JSON and HTTP/2 reuses connections. The gap matters most at high call volumes; for a typical web request, network latency dominates.
Can browsers use gRPC?
Not directly. Browsers don't expose the low-level HTTP/2 control that gRPC needs, so web apps use gRPC-Web or a gateway that translates between HTTP with JSON and gRPC.
Does gRPC use HTTP?
Yes. gRPC runs on top of HTTP/2, but it uses HTTP as a transport for binary messages rather than following REST conventions like resource URLs.