Why Size Matters on the Net

By Jennifer Farley | Nov 30 2006 |

The cost for the web space provided by an Internet Service Provider (ISP) is actually one of the lower costs involved in hosting a site. The biggest cost to a web hosting company is data transfer.

What is Data Transfer?
Data transfer is the amount of data that is transferred from the computer that is hosting a particular web site to everyone that is using it. It includes the downloading of everything that goes to make up the page, including HTML, images, sound and flash animations Often the term Bandwidth is misused and confused with data transfer. Although the two topics are related, bandwidth refers more to how fast the files can be downloaded rather than how much is downloaded. The more bandwidth a site has available, the quicker it can send files to your visitors and vice-versa.

Data transfer includes only the files that are used by the person visiting your site. So, it is possible that a site that uses over 100Mb in disk space can use only 10Mb a day in transfer, while a site using 2Mb of disk space may use 50Mb a day. Therefore, it is important not to confuse the amount of data transfer or bandwidth your site uses with the amount of disk space that it takes up

To illustrate the idea further: If a 1kb HTML file is visited 100 times a day, the page itself would use 100Kb of transfer for that day. If the same file had images, each of those would also be downloaded between 0 and 100 times for that day (depending if the visitor loaded the whole page) and the total transfer used by the site would increase by the size of each image (or other file embedded into the page such as a flash file or a sound file) multiplied by the number of times it was downloaded to visitor’s computers.

So why is File Size important
If you visit a site that contains many animated images, a flash file and possibly a music file, it is unlikely that you would stay to download it all if the files are anyway large in size. This is an example of the idea of wasted data transfer. All the bells and whistles you place on your website would quickly add up in terms of file size but if no one is staying to watch your Java applet presentation then it’s just a waste of both your transfer quota, and your visitors time. It is therefore important to build websites that are as small in size as possible (without sacrificing the design), even if you don’t pay much for your web space.

Reducing File Sizes
If your site is getting too near its data transfer limit for comfort then there are basically two things you can do to help minimise the effects.

Reduce the number of files on your server
Optimize your files for use on the web

Reducing the number of files on the server is only really effective in saving data transfer if you make the right choice about which files to delete. Deleting your least accessed files may seem like a logical choice, but if they are only being accessed 2 or 3 times a day then you are not going to make much of a saving.

The safest way of saving your transfer is to make sure that all your files are optimized for the web. Any file size savings you can make will add up to be a considerable saving on a busy site!

Optimize your images
When using GIF images (often used for logos and buttons on websites), try to use as few colours as possible without losing too much of the quality. When using JPG images (used mainly for photographic style images), experiment with different levels of compression.
Compress your HTML
It is important that the HTML used on the site incorporates the latest standards. Once your pages are following the standards, there are HTML compression tools available to squash any un-necessary code out of your pages.

Sound Quality
If you use sound files at all on your site and they are high quality, it is worth opening them up in suitable editor and experiment with saving them in different formats to see if you can get the same sort of quality by saving it in a different way.

The Basics
Finally, go through your each page in your site and make absolutely sure that you need everything that is currently appearing on these pages. For example, your Flash intro, is it for show purposes only or does it really have a function. Be ruthless!