Nginx
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
What detecting Nginx tells you about a site
Nginx is the modern default web server and reverse proxy, read straight off the Server: nginx response header (sometimes with a version). Its ubiquity makes it a weak identity signal, but the choice of Nginx over Apache leans toward newer, performance-conscious or high-concurrency setups — it commonly fronts an application server, terminates TLS and serves static assets. Detecting it tells you little about the app itself but confirms a conventional reverse-proxy architecture rather than a managed-edge platform doing the same job.
The detail that matters for Nginx
Whether the Server header includes a version number is a small ops tell: a bare nginx with no version means the operator deliberately suppressed it (a hardening habit), while a full nginx/1.x.y banner exposes the exact build for anyone checking patch level.
Nginx in a real-world stack
When you find Nginx, it rarely travels alone. Reverse-proxies almost any backend — PHP-FPM, Node, Python WSGI/ASGI, Java — and frequently sits behind a CDN as the origin server.
About
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Categories: Web servers, Reverse proxies
Quick facts
Detection methodology for Web servers
Server software identification reads the `Server` response header and (where exposed) version-specific markers in error pages. Cloudflare in front of nginx in front of Apache is the classic three-layer stack you'll see in the wild — we surface each layer separately so the actual origin server isn't masked by the edge layer.
How we detect Nginx
Sourcemap Explorer carries 2 fingerprint signals for Nginx, spread across 1 channel — response header. The exact patterns are listed below, and you can replay each one in Chrome DevTools to confirm a match by hand.
Each signal alone is rarely conclusive — Sourcemap Explorer cross-references all of them and weights by confidence. You can reproduce any of these checks yourself in Chrome DevTools.
Server-side fingerprint: the response header reveals the technology behind the page. Visible in DevTools → Network → response headers.
Server: nginx(?:/([\d.]+))?
X-Fastcgi-Cache:
FAQ
How do I check if a website is using Nginx?
Open the page in Chrome, click the Sourcemap Explorer toolbar icon, and read the Stack tab. Nginx's specific fingerprints here are response header, and the popup flags Nginx whenever any combination of them is found. The same checks can be reproduced manually in DevTools — see the "How we detect" section above.
What Nginx version can Sourcemap Explorer detect?
Nginx ships as a hosted web servers rather than a bundled npm package, so version-specific detection isn't always possible. Where the platform leaks a version in response headers (`X-Powered-By`, `Server`, generator meta tags) we surface it; otherwise we report presence only.
Where can I read more about Nginx?
Official site: https://nginx.org/en. For Sourcemap Explorer's detection guide, see the deep-dive link below or the related guides in the cross-link section.
Keep reading on Sourcemap Explorer
Alternative tools
Detected by Sourcemap Explorer
Open the popup on any page running Nginxand you'll see the exact version pulled from the bundled package.json when sourcemaps are exposed.