Mastering Nginx Rewrite: URL Redirection and Flag Options Explained

Rewrite in Nginx enables URL redirection without changing the address shown in the browser.

Purpose

It is commonly used for pseudo‑static URLs, e.g., converting /user/123 to /user.php?id=123.

Syntax

The basic directive is: rewrite regex replacement [flag]; where regex defines the matching rule, replacement is the target URL, and [flag] (optional) controls post‑rewrite behavior.

Rules

Rewrite can only be placed inside server{}, location{} or if{} blocks.

It operates on the part of the URL after the domain, excluding query parameters.

Examples

1. Redirect IE browsers to an /ie/ directory

if ($http_user_agent ~ MSIE) {
    rewrite ^(.*)$ /ie/$1 break;
}

2. Resize image requests

rewrite ^/images/(.*)_(\d+)x(\d+)\.(png|jpg|gif)$ /resizer/$1.$4?width=$2&height=$3 last;

3. Domain jump

server {
    listen 80;
    server_name jump.test.com;
    root /opt/www;
    rewrite ^/ http://www.test.com/;
}

4. Map a patterned directory to another rewrite ^/([0-9a-z]+)job/(.*)$ /area/$1/$2; 5. Convert a flat filename to a multi‑level path

rewrite ^/job-([0-9]+)-([0-9]+)-([0-9]+)\.html$ /job/$1/$2/jobshow_$3.html last;

Flag meanings

last : equivalent to Apache’s [L], stops processing further rewrite rules in the current location and restarts the search with the new URI.

break : stops processing any further rewrite directives in the current server block.

redirect : returns a 302 temporary redirect.

permanent : returns a 301 permanent redirect.

Note that last does not terminate the matching of the rewritten URL, while break does.