Prevent JavaScript Hotlinking with .htaccess

By  on  

Almost a decade (!) ago I wrote a post about preventing image hotlinking.  We all have the right to protect imagery hosted on our domain because it can slow our site down tremendously.  I love that post because it shows you how to replace the image requested with any image of your choosing; for example, I could replace any incoming image request with my logo:

<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteCond %{HTTP_REFERER} !^$
  RewriteCond %{HTTP_REFERER} !^https://davidwalsh.name/.*$ [NC]
  RewriteRule .*.(png|gif|jpe?g)$ [F,NC]
</IfModule>

But what should we do when someone is hotlinking JavaScript files?  I've written a ton about JavaScript over the years, oftentimes providing a demo page, so you can probably guess I host many JavaScript files, including all of my MooTools plugin files.  I've chosen a somewhat harsh approach to prevent hotlinking of JavaScript files:

<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteCond %{HTTP_REFERER} !^$
  RewriteCond %{HTTP_REFERER} !^https://davidwalsh.name/.*$ [NC]
  RewriteRule \.(js)$ http://davidwalsh.name/hotlink.js [R,L]
</IfModule>

The snippet above, placed in my .htaccess file, directs my server to ignore the JavaScript file the foreign domain has requested and instead provide a hotlink.js file whose contents are a bit devious:

window.location = 'https://davidwalsh.name/';

A bit harsh?  Perhaps, but my server is put under undue stress, they shouldn't be hotlinking files, and being redirected to my site is a good indication of where they should be looking to fix the issue.  I could do worse, like serve evil.js or redirect them to an adult site, but I'd prefer not to go that far.

Protect your server from hotlinking -- you have every right to and, in the end, you're probably doing them a favor.

Recent Features

  • By
    From Webcam to Animated GIF: the Secret Behind chat.meatspac.es!

    My team mate Edna Piranha is not only an awesome hacker; she's also a fantastic philosopher! Communication and online interactions is a subject that has kept her mind busy for a long time, and it has also resulted in a bunch of interesting experimental projects...

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

Incredible Demos

  • By
    Fancy Navigation with MooTools JavaScript

    Navigation menus are traditionally boring, right? Most of the time the navigation menu consists of some imagery with a corresponding mouseover image. Where's the originality? I've created a fancy navigation menu that highlights navigation items and creates a chain effect. The XHTML Just some simple...

  • By
    Google Font API

    Google recently debuted a new web service called the Font API.  Google's Font API provides developers a means by which they may quickly and painlessly add custom fonts to their website.  Let's take a quick look at the ways by which the Google Font...

Discussion

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