Part 9: How Nginx Maps Files to Domains and Creates Pretty URLs

Last updated: September 8th 2023


As web developers, we rely on web servers to efficiently serve our users' web pages. NGINX stands out among the various options available as one of the most popular and versatile choices. Of its many impressive features, one, in particular, is worth highlighting - its robust URL mapping system. This powerful feature allows us to define how the server should handle incoming requests. Understanding this mechanism is crucial for building responsive and efficient NGINX web applications.

This article will delve into a detailed explanation of NGINX's URL mapping system. We'll begin with an introduction to the fundamentals of URL mapping: what it entails and its different types of mappings that can be utilized effectively. Furthermore, we will look at advanced functionalities such as location blocks, regular expressions, and variables NGINX offers for seamless integration within our projects.

Whether you're a developer, system administrator, or IT manager, it's super important to understand how NGINX recognizes and maps files to your domain. This knowledge will help you troubleshoot issues and optimize your web application. Let's embark on this journey toward mastering NGINX's magnificent URL mapping capabilities!

What is URL mapping?

URL mapping, or routing, is a fundamental concept in web development. It involves defining how incoming URLs (Uniform Resource Locators) are processed and mapped to specific actions or resources within a web application. This process is crucial for creating user-friendly and organized web applications. Let's explore the fundamentals of URL mapping:

  1. URL Anatomy: A URL is essentially a string of characters that serves as the address for a specific resource on the web. It consists of multiple components that help identify and locate the desired resource:

       a. The protocol used to access the resource - http
       b. The domain name -
    c. The port number (optional) defaults to :80. If no specific port is provided, the default                   value of 80 will be used for HTTP connections.
       d. The path to the specific resource on the server - /path/to/resource
    e. Query parameters -  ?query=value - are a handy tool for adding additional data to a URL.            You can use this data to customize and enhance how the server processes and responds           to client interactions.
      f. A fragment identifier is an optional component to identify a specific resource portion -                #fragment.
  2. Role in Web Applications: URL mapping is usually handled by a component of the web application framework or the web server itself.
  3. Ability to handle routes: In modern web frameworks, URL mapping is often defined using routes and route handlers. A route is a pattern that matches a specific URL or URL pattern. When a request matches a route, a corresponding route handler is executed to generate the appropriate response. Routes can include parameters that capture dynamic segments of a URL.
  4. Inclusion of Verbs (HTTP methods): By taking into account the HTTP method used (like GET, POST, PUT, or DELETE), different routes can be defined for each method. This means that your application can handle a variety of requests in unique and effective ways.

So, how does NGINX recognize and map files to your domain?

Simply put, NGINX effortlessly maps files to domains through its configuration settings and request processing flow. Here’s a detailed explanation of how NGINX handles the recognition and mapping of the files to domains:

Configuration Files

NGINX uses configuration files to determine how it should handle incoming requests. The main configuration file is typically named nginx.conf, and additional files can be included for more efficient organization of settings.

Server Blocks

NGINX utilizes server blocks, also known as virtual hosts, to specify its response to requests for different domains or subdomains. Each server block contains configuration directives determining how requests for a particular domain should be handled. These server blocks are defined within the HTTP context of the configuration file. The following is an example configuration file:

server {
    listen 80;

    root /var/www/;    

    location / {

        try_files $uri $uri/ =404;


In the present instance, NGINX has been appropriately configured to actively monitor and listen on port 80 for requests pertaining to and It effectively maps these requests to the designated /var/www/ directory and seamlessly employs the try_files directive to thoroughly scrutinize and analyze the requested files within the said directory.

Location Blocks

Within a server block, you can also define location blocks to specify how NGINX should handle specific paths within a domain. Location blocks allow you to customize how different URL paths are processed and served. For example:

location /images/ {

    alias /var/www/;

    expires 1y;


Within the context of this example, all incoming requests directed towards the /images/ path shall be fulfilled by utilizing the /var/www/ repository. Additionally, it should be noted that the expires directive is employed to establish a cache-control header for these particular files.

Mapping Requests to Files

When a client requests a domain, NGINX uses server blocks' configurations to determine how to handle the request. It matches the requested domain using the server_name directive and then maps it to a specific file or directory on the server using an appropriate location block.

Proxying and Loading Balancing

In addition to serving static files, NGINX can also act as a reverse proxy for backend application servers. This is commonly used for load balancing or serving dynamic content generated by applications.

What are Pretty URLs?

Pretty URLs, also called clean or user-friendly URLs, are web addresses optimized for human readability and comprehension. By eliminating unnecessary elements like query parameters and file extensions, pretty URLs enhance a website's address's visual appeal and usability. They are crucial in improving the overall user experience by making navigation more intuitive and facilitating better recall of web page locations.

Benefits of Pretty URLs

Pretty URLs provide a heap of benefits to your website or web application from a user experience point of view. The following are some of the benefits of Pretty URLs:

Improved Readability

Pretty URLs are more human-readable and intelligible. By eliminating unnecessary elements like query parameters and file extensions, pretty URLs enhance a website's address's visual appeal and usability. They are crucial in improving the overall user experience by making navigation more intuitive and facilitating better recall of web page locations.


Search engines take into account the keywords in URLs when determining their rankings. Therefore, having relevant keywords in a visually appealing URL can enhance search engine optimization (SEO).

Increased Shareability

Users are more likely to share clean and concise URLs, which can lead to improved user engagement and increased traffic.

Increased Trust

Clear and logical URLs contribute to user trust and credibility, as users can quickly identify the content they are accessing.

How do Pretty URLs work?

Web servers like NGINX and Apache utilize URL rewriting techniques to create user-friendly URLs. This involves internally redirecting requests for a pretty URL to a script or resource that handles the request.

For example, a web server might rewrite the Pretty URL - to the actual resource that processes such requests, such as

In NGINX, the rewrite directive within a location block performs URL rewriting. You can achieve this by using regular expressions and configuration rules. For example:

location /articles {

    rewrite ^/articles/(\d+)$ /article.php?id=$1 last;


In this example, the URL /articles/145 is internally rewritten to /article.php?id=145. The last flag indicates that no further processing is required.


And there you have it! The mechanism of NGINX mapping and pretty URLs demystified. URL mapping is a fundamental concept that allows developers to create structured and user-friendly web applications. It's like making a roadmap for your website, defining how URLs are processed and linked to specific actions or resources. By determining how URLs are processed and related to particular actions or resources, you can ensure that users have an intuitive browsing experience while also optimizing your site for search engines.

With this newfound knowledge, you can confidently navigate the web like a pro, effortlessly routing requests and serving beautiful, clean URLs.  So go ahead and map out those URLs and make navigating the web a breeze! Happy mapping!

Meet Aayush Nair, a WordPress website designer with almost a decade of experience who doesn’t only craft visually appealing websites but also has a knack for writing engaging technology blogs. In his spare time, he enjoys illuminating the minds around him.

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