API gateway vs. reverse proxy: roles and tradeoffs

Compare API gateways and reverse proxies by routing, authentication, rate limits, and operations, and decide when an additional layer is useful.

Guance Editorial Team 2026-10-27 4 min read Updated 2026-10-27

Best practices

Illustration of application infrastructure and operations

A reverse proxy receives requests on behalf of backend services. An API gateway combines that traffic-forwarding role with policies for API consumers: authentication, quotas, request transformation, and API-specific routing. The distinction is about responsibility; the capabilities of individual products overlap.

For a small set of web services, a reverse proxy may cover everything you need. A gateway becomes useful when many APIs need a consistent policy and management interface.

Compare their responsibilities

Area	Reverse proxy	API gateway
Main role	General traffic entry point	API entry-point policy; lifecycle management varies by product
Load balancing	A common core function	Commonly supported alongside API policies
TLS termination	Commonly supported	Commonly supported
Caching, compression, static files	Often available with configuration	Caching and compression may be available; static files often belong elsewhere
Authentication and authorization	Built-in modules, external authorization, or extensions	Often exposed through policies or plugins; verify supported schemes
Rate limits and quotas	Can use configurable keys and rules	Often organized around consumers, applications, or APIs; exact capabilities vary
Request and response transformation	URL and header rewriting; body/protocol support depends on extensions	Transformation plugins may be available; verify supported payloads and protocols
API versions	Can route by path or header	Routing and policies are common; broader lifecycle management may require another platform component
Service aggregation	Usually extensions or application code	Available in some products, not a universal built-in feature
Analytics and metering	Logs and metrics, often exported to other systems	May include consumer-level analytics and usage accounting, depending on the product

Common implementations

Nginx, HAProxy, Traefik, and Envoy are widely used as reverse proxies. Kong, Apache APISIX, Spring Cloud Gateway, and Amazon API Gateway provide gateway-oriented capabilities.

These categories are not mutually exclusive. Kong and APISIX build on Nginx/OpenResty, and other gateways use Envoy. A gateway often combines a proxy data plane with a management and policy layer. Check the edition, plugins, and deployment model before assuming a particular feature is included.

Choose around the work you need to do

A reverse proxy is often sufficient for:

A monolith or a few web services needing HTTPS and load balancing.
Static content, caching, compression, and straightforward forwarding.
Simple routing between internal services.

Consider an API gateway when you need:

A common entry point for many independently maintained APIs.
Third-party consumer credentials and usage quotas. Billing may require additional integration.
Consistent authentication, rate limits, and staged routing policies.
API-level usage analysis and version policies.

Both layers can coexist. An external Nginx instance or cloud load balancer may terminate TLS and forward to a gateway, which then applies API policies. Each extra hop needs a clear purpose.

After adding a layer, compare latency and error rates for the same workload and correlate request identifiers across both access logs. Guance's Nginx integration can collect entry-point metrics. Identify whether the source is the basic status module, VTS, or Nginx Plus: basic connection counts do not provide upstream request latency.

Frequently asked questions

Do I still need Nginx behind an application load balancer?

Not necessarily. An HTTP-aware load balancer already performs reverse-proxy functions, including routing and often TLS termination. Add another proxy only for requirements the load balancer does not meet, such as particular caching or custom routing behavior.

How does a service mesh fit in?

Gateways commonly govern traffic entering a system, while service meshes commonly govern service-to-service traffic. This north–south/east–west distinction describes typical roles, not a hard product boundary. They can complement each other on policy, security, and reliability.

How much latency does a gateway add?

There is no universal figure. TLS, payload size, plugins, external authorization, connection reuse, and available resources all matter. Measure throughput and tail latency with your intended configuration. This article does not report benchmark results.