Caveats

1. Your server must allow .htaccess files for this technique to work.
2. If you do not have a .htaccess file in your root directory, see the related FAQ first.
3. Do not use this method to redirect image hot links to HTML pages or to servers that are not your own.
4. Hot linked images can only be replaced by other images, not with HTML pages.
5. As with any .htaccess rewrite, you may block legitimate traffic, such as users behind proxies or firewalls.

Directions

1. Create a jpeg image called no_hot_link.jpe. Note that the odd file extention (.jpe) is intentional and important. Place this file in your images directory.
2. Place the following code in the .htaccess file of your root directory.

RewriteEngine On
RewriteCond %{HTTP_REFERER} !^http://(.+\.)?your_site\.com/ [NC]
RewriteCond %{HTTP_REFERER} !^$
RewriteRule .*\.(jpe?g|gif|bmp|png)$ /images/no_hot_link.jpe [L]

Explanation

The first line begins the Apache rewrite rule. The second line matches any requests from your own site, here called your_site.com url. The [NC] flag means "No Case", which means, match upper and lower case characters. The third line allows empty referrals. The last line matches any files ending with the extension jpeg, jpg, gif, bmp, or png. This is then replaced by the no_hot_link.jpe file in your images directory. This JPEG file uses the extension jpe instead of jpg to prevent these rules from blocking your replacement image. Block hot linking from specific domains

To stop hotlinking from specific domains only, such as myspace.com, blogspot.com and livejournal.com, while allowing other web sites to hotlink to your images, use the following code:

RewriteEngine On
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?myspace\.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?blogspot\.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?livejournal\.com/ [NC]
RewriteRule .*\.(jpe?g|gif|bmp|png)$ /images/nohotlink.jpe [L]

You can add as many different domains as you want. Every RewriteCond line except the last one should end with the [NC,OR] flags. NC means to ignore case. OR means "Or Next", as in, match this line OR the next line. The last RewriteCond omits the OR flag to stop matching after the last RewriteCond.

Display a 403 forbidden code

Alternatively, you can display a 403 Forbidden error code. Replace the last line of the previous examples with this line:

RewriteRule .*\.(jpe?g|gif|bmp|png)$ - [F]