Beginner Tip:
Outwit Bandwidth Thieves

by Larisa Thomason,
Senior Web Analyst,
NetMechanic, Inc.

Imagine receiving a huge electric bill from your utility company that's ten times larger than you expected. You're confused until you notice that your neighbors have stretched a bunch of extension cords over to your house. They're using your electricity to run their appliances, stereos, and computers! You can have similar problems online if bandwidth thieves target your Web site.

Hotlinking Is A Hot Topic

Bandwidth is the total amount of resources used by a Web site during a certain period - usually a month. It's calculated in bytes of data downloaded to visitors. Every time a visitor comes to your site and requests a page, you're using bandwidth. All the files that download to the visitor's browser cache - images, navigation buttons, sound files, Flash presentations, etc. are counted in your bandwidth total.

Bandwidth theft (also called "hotlinking" or "direct linking") occurs when external Web sites link directly to images, music files, or other multimedia applications on your Web site.

Think about how you include a regular image link on your page:

<IMG src="image.jpg" height="350" width="200" alt="mage description">

That HTML code tells the browser to request the image file from the same server the rest of the site information is coming from.

But with a hotlink, the visitor's browser gets the page content from the site that's stealing from you, but calls up your server and asks for the image file or other stolen file! The code for a hotlink works like this:

<IMG src="http://www.YourSite.com/image.jpg" height="350" width="200" alt="image description">

That means every time the bandwidth theft site gets a visitor, that visitor's browser hits your server for the hotlinked files and your bandwidth count for the month increases.

If the site stealing your bandwidth gets a lot of traffic, you could be in a lot of trouble with your Web host.

Going Over The Limit

Check your Web hosting agreement. Chances are there's a limit to the bandwidth you're allowed to consume each month. Many Web hosts charge extra per month when you exceed that limit.

One reason is that most low-cost hosts offer virtual hosting plans. Multiple sites reside on a single server, so when one site hogs all the bandwidth, it affects the download performance of every other site on the server.

Your site could suffer severe consequences if someone else steals your bandwidth.

Track Down The Thieves

Unfortunately, most sites don't discover the theft until they get the big bill from the hosting company. Catch the problem early by looking at your server logs.

Study them closely for any unusual increases in traffic. If the traffic is spread evenly across file types, then congratulations! You've probably successfully used Search Engine Power Pack to boost your site to the top of the rankings and you're getting a lot of new visitors.

You should be worried though if the traffic is mostly requests for a single file - like an image, music, or multimedia file. There's a good chance that someone has linked directly to your file and is displaying the content on their site.

align="justify"It should be easy to find the offender's IP address in your server logs. But you can also just go to one of the search engines that let you search for images and alternative file formats. Enter your filename and quickly find out if it's in use on any other sites.

Be sure to actually visit the site before you accuse the webmaster of theft! If you have a common file name like cat.jpg, you can't immediately assume that every file on the Web named cat.jpg is stolen from your site.

Stopping Bandwidth Theft

Ok, so you've located the bandwidth thief. What should you do?

Be careful though that you don't break links on your own site when you change file names. Use HTML Toolbox's link checker to validate your links each time you change a file name, directory name, or path.

Watch Page Download Time

While bandwidth theft can be fatal to your site and your wallet, overall page download time should concern you even more. You'll only attract visitors and get them to come back if your page downloads quickly.

Unless you're using Flash or other multimedia applications, most of your total bandwidth and download time will come from your image files.

NetMechanic offers a free, easy-to-use graphics tool called GIFBot. Use it to reduce the file size of your JPEG and GIF images without decreasing the display size or sacrificing the quality of the image. In many cases, you can decrease the file size by 50% or more and still have an attractive image.

After you've optimized your images and uploaded them to your server, use HTML Toolbox to check your pages. It alerts you to slow-loading pages, broken links, browser-specific code, and other techniques that may cause problems.

Bandwidth theft may cost you a lot of money, but slow-loading pages cost you a lot of visitors!