How To Redirect Specific URLs In Nginx?

Website Restructuring

Website restructuring requires redirecting old URLs to new structures. This process helps maintain user experience during site changes. When you update your website's organization, you need to make sure visitors can still find the content they're looking for. By setting up redirects, you guide users to the correct pages on your updated site, reducing confusion and potential loss of traffic.

Custom URL Shortening

Custom URL shortening is another use for redirects. This technique creates short, memorable URLs that point to longer web addresses. Short URLs are easier to share, especially on platforms with character limits like social media. They also improve link tracking, as you can create unique short URLs for different marketing campaigns or sources. By using Nginx to handle these redirects, you can manage your custom short URLs and direct users to the full, original web addresses.

server {
    listen 80;
    server_name example.com;

    location /short1 {
        return 301 https://www.example.com/very/long/url/path;
    }
}

Configuring Nginx Server Blocks

To set up URL redirects in Nginx, you need to work with server blocks. The Nginx configuration file is usually at /etc/nginx/nginx.conf or /usr/local/nginx/conf/nginx.conf. Server blocks are in this file and define how Nginx handles requests for domains or IP addresses.

A basic server block structure:

server {
    listen 80;
    server_name example.com;

    # Configuration directives go here
}

Writing Redirect Rules

To create redirect rules, use the location directive within a server block. The syntax for a basic redirect:

location /old-url {
    return 301 /new-url;
}

For specific URLs, use exact matches:

location = /exact-old-url {
    return 301 /exact-new-url;
}

You can use regular expressions for flexible matching:

location ~ ^/old-prefix/(.*)$ {
    return 301 /new-prefix/$1;
}

Implementing 301 (Permanent) Redirects

When setting up redirects, you can choose between 301 (permanent) and 302 (temporary) redirects. A 301 redirect tells search engines that the page has moved permanently, while a 302 indicates a temporary move.

The main difference is how search engines treat them:

• 301 redirects: Search engines transfer most of the SEO value from the old URL to the new one.
• 302 redirects: Search engines keep the old URL in their index, assuming the move is temporary.

Using 301 redirects for permanent changes offers SEO benefits:

1. It helps maintain search engine rankings for the redirected pages.
2. It consolidates link equity from old URLs to new ones.
3. It provides a better user experience by directing users to the correct content.

To implement a 301 redirect in Nginx, use this syntax:

return 301 $scheme://newdomain.com$request_uri;

This redirects all requests to a new domain while keeping the original path and query parameters.

location /old-page {
    return 301 /new-page$is_args$args;
}

Using Regular Expressions for Dynamic Redirects

Regular expressions in Nginx help you create flexible redirect patterns. These patterns can match multiple URLs and redirect them based on specific parts of the original URL.

To use regular expressions in Nginx redirects, add the ~ symbol before the location pattern:

location ~ ^/old-section/(.*)$ {
    return 301 /new-section/$1;
}

This rule redirects any URL starting with /old-section/ to /new-section/, keeping the rest of the URL path intact.

You can capture multiple parts of the URL:

location ~ ^/category/([^/]+)/([^/]+)$ {
    return 301 /new-layout/$1-products/$2;
}

This rule would redirect /category/electronics/laptops to /new-layout/electronics-products/laptops.

location ~* ^/old-section/(.*)$ {
    return 301 /new-section/$1;
}

Handling Query Parameters in Redirects

Preserving or changing query strings during redirection is often needed to maintain functionality or tracking information.

To preserve all query parameters in a redirect, use the $is_args$args variables:

location /old-page {
    return 301 /new-page$is_args$args;
}

This redirect keeps all original query parameters intact.

To change specific query parameters, you can use the set directive with regular expressions:

location /product {
    if ($args ~ ^id=(\d+)) {
        set $product_id $1;
        return 301 /new-product-page/$product_id;
    }
}

This rule extracts the product ID from the query string and includes it in the new URL path.

You can also add new query parameters or change existing ones:

location /search {
    return 301 /new-search?source=old&$args;
}

This adds a source=old parameter to the query string while keeping all original parameters.