What is hotlinking?

Hotlinking occurs when another website directly links to your web site's files, primarily images and/or videos. When a person hotlinks one of your files they use the direct link for that file and in doing so use your server resources (bandwidth) to bring up that file every time it is accessed on their website.

In other words, imagine you are paying the electricity bill for you house and a neighbor starts plugging in their appliances into your sockets. The end result, you end up paying for electricity your neighbor's electricity usage and your own.

How do you ensure you are not hotlinking?

When posting images or videos on your website, ensure that they are stored locally on your server and you reference the local version.

Local Image Reference
<img src="image.jpg" height="350" width="200">

This image tag is pulling from an internal location within your website and therefore using your own bandwidth.

Hotlinking Image Reference
<img src="http://notsite.com/image.jpg" height="350" width="200">

This image tag is referencing an image that is stored on another website's server and therefore whenever that image is displayed it is using the other website's bandwidth.

To avoid hotlinking other websites' images you can:

• Not link to files on other servers that do not belong to you
• Upload files to your own server's directory via a file uploader or FTP
• Utilize a free media hosting service like Flickr, YouTube, or Picasa that allows for direct linking 

How can I find out if my images or files are being hotlinked?

Your first option should be to review your analytics and review files that are receiving a lot of views in comparison to your average page views. If you identify any image or video files that have an unusual amount of traffic, take a look to determine where that traffic is coming from and review those sources to see if they are directly linking to your files. Google Analytics is useful for this exercise.

Another option would be to search for your images in Google Image search to see if they come up. If additional results for your exact image show up in Google's results, then you can track down the website that is hotlinking your file.

How can I stop or avoid my images from being hotlinked?

A first step would be to watermark all of your images. While this will not necessary prevent hotlinking altogether, it will make it much less desirable for another website to directly link to an image that has your watermark. A typical watermark would include a copyright and your business name.

To combat an offending website you can also switch your image files so that instead of the desired image, you replace it with a blank image that has a message notifying visitors that the website is stealing content. To do this you can simply rename your existing file and modify how you reference that image in your website and replace that image with your new blank image.

To combat hotlinking directly, you can contact the site owner and ask them to remove your files. A number of times it is a simple mistake and the website owner may oblige. Alternatively, you can submit a DMCA claim to their ISP and/or with Google.