This is targeted mainly towards server administrators running IIS, but if you’re just an internet user, you may find it of some value too.

Jeff Atwood, over at his Coding Horror blog, briefly touched on HTTP compression a while back, following it up with a post involving IIS 6.0 and compression, and later a post regarding using a .NET HttpModule to handle compression in ASP.Net sites. You should definitely read these posts if you have no idea what HTTP compression is. Don’t worry, I’ll wait. Back? Good.

I had been using the HttpModule approach for a while, with the well-made (and free) blowery HttpCompressionModule. I have run into some problems, though. There are some redirect actions that can cause the module to fail, as well as other documented problems. Plus, the module does nothing to compress non ASP.Net content, such as ASP pages, style sheets and javascript files.

In doing more researching, I came across IISXpress, another free (for personal use only, not on a server) HTTP compression program. This one hooks into ISAPI, which means that any content that IIS serves wil be passed through this program for compression. IISXpress allows you to define content types you wish to include/exclude, as well as directories.

I really liked how IISXpress showed a history of every file it compressed, and what the savings were. There’s no guessing on my side if it’s working or not. I know it is from the history’s output. I liked the program so much that I decided to buy it almost immediately. $50 well spent!

If you run a web server, you owe it to yourself to research HTTP compression. It will allow you to serve the same content, but using less bandwidth in the process. And your end-users won’t need to do anything special!