# Rewriting URLs with the mod_rewrite module

> Use mod_rewrite rules in .htaccess to create clean URLs, force HTTPS, remove .php extensions and add trailing slashes.

Source: https://helpcenter.ruachost.com/developers/web-servers/rewriting-urls-with-the-mod-rewrite-module/

The **mod_rewrite** module in Apache allows you to rewrite URLs dynamically. On **ruachost.com**, you can use it to create cleaner, SEO‑friendly links, hide internal implementation details, and redirect visitors to secure connections.

## Why Use mod_rewrite?

- **SEO benefits**: Search engines prefer human‑readable URLs.
- **Security**: Hide query strings and internal file structures.
- **User experience**: Provide simple, memorable links.
- **Flexibility**: Redirect traffic based on conditions (e.g., HTTPS enforcement).

## Enabling mod_rewrite

- On most Ruachost shared hosting accounts, `mod_rewrite` is already enabled.

## Basic Example: Clean Product URLs

Instead of:

```
http://www.example.com/products.php?id=232&cat=11
```

You can rewrite to:

```
http://www.example.com/products/calculator
```

```
```

### `.htaccess` Rule:

```
RewriteEngine On
RewriteRule ^products/calculator$ /products.php?id=232&cat=11 [L]
```

- `RewriteEngine On` → enables rewriting.
- `RewriteRule` → matches incoming URL and maps it to the target file.
- `[L]` → stops processing further rules once matched.

## Common Use Cases

### 1. Redirect to HTTPS

```
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
```

### 2. Remove `.php` Extension

```
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^([^/]+)$ $1.php [L]
```

### 3. Force Trailing Slash

```
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^(.+[^/])$ %{REQUEST_URI}/ [R=301,L]
```

## Testing Your Rules

- Use browser developer tools to confirm redirects.
- Check Apache error logs if rules don’t work.
- Avoid infinite loops by testing carefully.

> **Important Notes:**
- Place rules in the `.htaccess` file in your site’s root (`public_html`).
- Order matters — rules are processed top to bottom.
- Always back up `.htaccess` before editing.
- Misconfigured rules can cause **500 Internal Server Errors**.