What is a reverse proxy
A reverse proxy is a server that sits in front of a website and gets every request before the site's own server does.
It decides where each request goes, then sends the answer back to the visitor. A reverse proxy is a gatekeeper on the website's side of the connection. Visitors and crawlers only ever talk to the proxy.
Reverse proxy defined for marketers
For a marketer, a reverse proxy is the layer that controls how your site answers people and bots. Content delivery networks such as Cloudflare run reverse proxies, and so do web servers like Nginx. Your developers set one up years ago and never mentioned it. Ask them whether you have one. Its settings can change what Google and AI crawlers receive.
How a reverse proxy works
A reverse proxy catches each request at the domain's public address and forwards it to a server behind it. When a browser asks for a page, the proxy checks its rules first. Its rules determine when it serves a stored copy or blocks the request. If it does neither, it passes the request to the origin server, which is the machine that holds the real site, and then relays the reply. Because every setup has its own rules, the same proxy can treat a browser and a bot differently.
Reverse proxy vs forward proxy
A forward proxy acts for the user, and a reverse proxy acts for the website. A company sends staff traffic through a forward proxy so the sites they visit can't see who they are. A reverse proxy hides the website's servers from visitors and controls how requests reach them. To tell them apart, check whether the proxy belongs to the person who browses or to the site.
Why it matters for SEO
A reverse proxy matters for technical SEO because it decides what Googlebot receives when it crawls your pages. A well-configured proxy caches pages and cuts load times, which helps page speed scores. A badly configured one can send crawlers server errors or bot blocks, even though the site looks fine in your browser. Teams also use proxies to serve a blog from a subfolder such as /blog instead of a subdomain. If rankings drop for no clear reason, check the proxy's logs and firewall rules before you rewrite any content.
How AI assistants use it
AI assistants reach your reverse proxy every time their crawlers fetch a page. Crawlers such as OpenAI's GPTBot and PerplexityBot identify themselves by name, and the proxy can allow or refuse each one. Bot-protection rules on a content delivery network can block these crawlers without anyone in marketing knowing. If your pages never show up in ChatGPT or Perplexity answers, run an SEO audit and ask your developers whether the proxy lets those bots through.
A simple real-world example
A shop runs its store on one platform and its blog on another, but it wants both at shop.com. A reverse proxy at shop.com sends every /blog request to the blog server. All other requests go to the store. Visitors and search engines see one domain, so the blog's articles count as part of the main site.
Related terms to know
Three other terms come up next to reverse proxies, and each covers a narrower or different job. Knowing them makes it easier to follow a conversation with your developers.
Content delivery network (CDN)
A content delivery network is a group of servers around the world that store copies of your pages close to visitors. CDNs work as reverse proxies, but their main job is speed and protection. Every CDN is a reverse proxy, but a reverse proxy doesn't have to be a CDN.
Load balancer
A load balancer spreads incoming traffic across several servers so that no one machine gets overloaded. It's a reverse proxy with one focused task. You'll find one on high-traffic sites.
Origin server
The origin server holds the website's real files and code. It sits behind the proxy and only answers the requests the proxy passes along. In that layout, the reverse proxy is the server that stands guard in front of the origin.