What Is a Reverse Proxy? A Plain-English Guide for Developers
Reverse proxies sit between users and your origin server to add caching, SSL termination, and routing. Learn how they work and when to use one.
TL;DR — Quick Answer
A reverse proxy accepts client requests on behalf of one or more origin servers. It can terminate SSL, cache responses, compress content, and route traffic — all transparently to the end user.
Definition
A reverse proxy is a server that sits between client devices and one or more origin servers. It intercepts client requests and forwards them to the appropriate backend, then returns the server's response to the client. [1]
From the client's perspective, the reverse proxy is the server — it never communicates with the origin directly.
Forward Proxy vs Reverse Proxy
| Concept | Forward Proxy | Reverse Proxy |
|---|---|---|
| Represents | The client | The server |
| Client awareness | Client configures it | Client is unaware |
| Common use | VPNs, corporate firewalls | Load balancers, CDNs, API gateways |
What a Reverse Proxy Can Do
SSL Termination
The proxy handles the HTTPS handshake with the client. Traffic between the proxy and origin can be plain HTTP (on an internal network) or HTTPS. This offloads SSL processing from your origin servers. [2]
Caching
The proxy stores copies of frequently-requested responses. Subsequent requests for the same resource are served from cache without hitting the origin — reducing latency and origin load. [3]
Load Balancing
A reverse proxy can distribute incoming requests across multiple origin servers, preventing any single server from becoming a bottleneck. [4]
Request/Response Transformation
Headers can be added, removed, or modified. Responses can be compressed, rewritten, or converted (e.g. HTML → Markdown).
Security
The origin's IP address is hidden from clients. The proxy can apply rate limiting, WAF rules, and bot detection before requests reach your application.
How Edgely Uses a Reverse Proxy
Edgely runs as a Vercel Edge Middleware — a reverse proxy executing in hundreds of edge locations worldwide. When a visitor hits your custom domain, the request reaches the nearest Edgely edge node, which looks up your domain configuration in Vercel Edge Config (sub-millisecond), fetches the response from your origin (Lovable, Framer, Webflow, etc.), and returns it to the visitor — all within a single HTTP round trip. [5]
Edgely is the fastest way to proxy your your app project to a custom domain. It provisions a free SSL certificate, syncs routing to Vercel Edge Config for sub-millisecond lookups, and optionally caches responses at the edge — all for free on the starter plan.
Key Takeaways
- A reverse proxy represents the server, not the client — clients never contact the origin directly.
- Core features: SSL termination, caching, load balancing, security, and response transformation.
- Edge reverse proxies run close to users, reducing latency significantly.
- Edgely uses Vercel Edge Middleware as an edge reverse proxy with sub-millisecond domain lookups.
Frequently Asked Questions
What is the difference between a CDN and a reverse proxy?
A CDN is a specialised reverse proxy optimised for caching and geographic distribution. All CDNs are reverse proxies, but not all reverse proxies are CDNs. A CDN stores content in many locations worldwide to minimise latency; a generic reverse proxy may not do any caching.
What is SSL termination?
SSL termination means the reverse proxy decrypts the HTTPS traffic from the client. The connection between proxy and origin can then be encrypted or unencrypted. This offloads cryptographic processing from origin servers.
Can a reverse proxy improve website performance?
Yes — through caching (fewer origin requests), compression (smaller payloads), and geographic proximity (edge nodes closer to users than the origin server).
Is Nginx a reverse proxy?
Yes. Nginx is commonly used as a reverse proxy, load balancer, and web server. Other popular reverse proxies include Caddy, Traefik, HAProxy, and Cloudflare.
What is an edge reverse proxy?
An edge reverse proxy runs at network edge locations (geographically close to users) rather than in a single datacenter. This reduces round-trip latency because requests are handled near the user before being forwarded to the origin.
Sources & Citations
- [1]Reverse Proxy (Cloudflare Learning Center)— cloudflare.com
- [2]SSL Termination (Nginx Docs)— docs.nginx.com
- [3]HTTP Caching (MDN)— developer.mozilla.org
- [4]Load Balancing Algorithms— nginx.com
- [5]Vercel Edge Config— vercel.com
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