Prevent Image Hotlinking With .htaccess and mod_rewrite

By  on  

One way to kill your website's bandwidth and overall download speed is to not block image "hotlinking." What's hotlinking? Hotlinking is linking to a file on an external server that the Web Developer does not own (most of the time the Web Developer doesn't even have permission to use the file). Hot linking occurs mostly with images.

Why would another website hotlink to a file on your server? There are a variety of reasons, both innocent and evil:

  • To use up the other website's bandwidth / save your bandwidth (evil)
  • To link to an oft-changing file so that the file is always up to date on your website (mostly innocent)
  • Laziness (both)

How can this be prevented? Relatively easily using some quick .htaccess directives.

The Code

The following prevents any domain beside yours from hotlinking:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www.)?yourwebdomain.com(/)?.*$ [NC]

The following allows only a friend to hotlink -- everyone else is barred:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www.)?yourwebdomain.com(/)?.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www.)?friend1domain.com(/)?.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www.)?friend2domain.com(/)?.*$ [NC]

The following allows for protection of only specified file extensions:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www.)?yourwebdomain.com(/)?.*$ [NC]
RewriteRule .*.(gif|jpe?g)$ [F,NC]

The following returns a "stop stealing my images" image:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www.)?yourwebdomain.com(/)?.*$ [NC]
RewriteRule .(gif|jpe?g|png|bmp)$ /graphics/stop-stealing.jpg [L,NC]

You can use the above coding practices to prevents thievery of any type of file you'd like, including CSS, JavaScript, and text files.

Recent Features

  • By
    JavaScript Promise API

    While synchronous code is easier to follow and debug, async is generally better for performance and flexibility. Why "hold up the show" when you can trigger numerous requests at once and then handle them when each is ready?  Promises are becoming a big part of the JavaScript world...

  • By
    39 Shirts – Leaving Mozilla

    In 2001 I had just graduated from a small town high school and headed off to a small town college. I found myself in the quaint computer lab where the substandard computers featured two browsers: Internet Explorer and Mozilla. It was this lab where I fell...

Incredible Demos

  • By
    Introducing MooTools LinkAlert

    One of my favorite Firefox plugins is called LinkAlert. LinkAlert shows the user an icon when they hover over a special link, like a link to a Microsoft Word DOC or a PDF file. I love that warning because I hate the surprise...

  • By
    pointer Media Query

    As more devices emerge and differences in device interaction are implemented, the more important good CSS code will become.  In order to write good CSS, we need some indicator about device capabilities.  We've used CSS media queries thus far, with checks for max-width and pixel ratios.

Discussion

  1. Nicely done!

  2. Brill, I appreciate this may be an old post, but its the answer I needed to fix my lil hotlinking problem so I thought I should say ta …

    TA!!

  3. Perhaps you could help. I’m trying to simplify for some of my clients moving to a cdn platform. for dev I’m using google app engine, just becasue, but files on the prod cdn will be served up the same way. Issue – we would to use .htaccess to have css|js|gif|jpg etc.. files be taken from the cdn by rewrite of the request, so we don’t need to change all the php and related files.

    IE.

    page is rendered with like to image http://example.com/images/image.gif

    but the image should be served from http://example-cdn.com/images/image.gif

    the folder sturcture could remain the same, just the domain would change from example.com to example-cdn.com

    Any idea’s?

  4. Jorge

    Hi, I’m looking at a solution like the one that replaces the images with a generic one (i.e. “stop stealing my images”).
    Can you clarify why it’s not going into an infinite loop? since it’s redirecting to *another* .jpg file -wouldn’t this create infinite redirects to the same image? –thanks!

    RewriteEngine on
    RewriteCond %{HTTP_REFERER} !^$
    RewriteCond %{HTTP_REFERER} !^http://(www.)?yourwebdomain.com(/)?.*$ [NC]
    RewriteRule .(gif|jpe?g|png|bmp)$ /graphics/stop-stealing.jpg [L,NC]
    

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!