Forward proxy vs Reverse proxy
A forward proxy and a reverse proxy are both intermediary servers that sit between clients and servers, but they serve different purposes and operate in opposite directions.
Forward Proxy
- Direction: Acts on behalf of the client (e.g., a user’s browser).
- Purpose:
- Helps clients access resources on the internet indirectly.
- Often used for privacy (hiding the client’s IP), bypassing restrictions (e.g., geo-blocking), or caching content to speed up requests.
- How it works:
- The client sends a request to the forward proxy.
- The proxy forwards the request to the destination server (e.g., a website).
- The server responds to the proxy, which then sends the response back to the client.
- Example: A company might use a forward proxy to monitor or filter employee internet traffic. VPNs can also act like forward proxies in some cases.
- Perspective: Client-side tool.
Reverse Proxy
- Direction: Acts on behalf of the server (e.g., a web server).
- Purpose:
- Protects servers, balances traffic (load balancing), caches content, or provides security (e.g., DDoS protection).
- Hides the server’s identity and internal structure from clients.
- How it works:
- The client sends a request to the reverse proxy (thinking it’s the actual server).
- The proxy forwards the request to one or more backend servers.
- The backend server responds to the proxy, which then sends the response back to the client.
- Example: A website like Netflix might use a reverse proxy to distribute incoming traffic across multiple servers for efficiency. Tools like NGINX or Cloudflare often function as reverse proxies.
- Perspective: Server-side tool.
Key Difference
- Forward Proxy: Client → Proxy → Server (focuses on the client’s needs).
- Reverse Proxy: Client → Proxy → Server (focuses on the server’s needs).
In short, a forward proxy serves the client by acting as its gateway to the internet, while a reverse proxy serves the server by managing incoming traffic and shielding the backend infrastructure.