The data sent by your web server to your users is probably not compressed. This means the original file will be sent without any attempt to reduce it's size. Many file types can be compressed very effectively, sometimes to as much as 10% of their original size. This means that a 1MB file in compressed form will occupy the same space as a 100KB file. The effect of this is to reduce the amount of bandwidth used by your web server and also to reduce the download time experienced by your users.

Most common web content files will compress to between 50% and 25% (2:1 and 4:1) of their original size.

Server versions of IIS support basic compression functionality. Workstation versions do not support compression. Compression is not enabled as default when IIS is installed, you need to switch it on via the Administration tool. There is no user interface for fine tuning your configuration or monitoring effectiveness.

Data compression is a well established technology which can reduce the size of a file by a significant margin without losing any of the original data. The compression mechanism looks for repeated patterns in the source file and removes the unnecessary data from the file. IISxpress uses the ZLIB and GZIP 'deflate' algorithm as specified in the HTTP/1.0 and HTTP/1.1 standards for maximum compatibility and performance.

IISxpress supports IIS versions 5.1 and above. This effectively means Windows XP Professional, Windows 2003, Windows Vista and Windows 2008 are supported.

IISxpress supports Windows XP Professional, Windows 2003, Windows Vista and Windows 2008.

No, compression is included in the HTTP/1.0 and HTTP/1.1 standards for transfer of web site data. Almost all client browsers support compressed responses, even if they don't they will still operate since IISxpress will not send compressed responses to clients which can't or won't accept it.

Your users will notice your web site being more responsive because less data is being transferred to them, also your bandwidth usage will be reduced allowing you to serve more users simultaneously. However there is a price to pay, normally your web server will not use much CPU time (unless you have a lot of intensive ASP, ASP.NET or CGI running), with compression enabled your CPU will take more of the strain.

To get an idea of how well your web site will compress use a program like GZIP or WINZIP to compress the files in your web site's directories. This will give you a fairly accurate idea of what kind of gains you are likely to get. Alternately, once IISxpress is installed, you can use a tool like Fiddler or WebLoad to profile the responsiveness of your server and the size of the pages being downloaded by your users.

There are a number of possible reasons for this. You may have exclusion rules which are preventing the responses from being compressed, try running with a clean configuration. If that is unsuccessful try switching on filter logging and view the resulting log files. If there is no request/response activity data in the log file then the ISAPI filter has not been installed correctly, try using the Repair option in the IISxpress Status Window. If you contine to experience problems then please contact Technical Support for assistence.

IISxpress has been tested with today's most popular browsers, the list includes Internet Explorer (5, 6, and 7), Opera (7, 8 and 9), Mozilla (1.x), Firefox (1, 2 and 3), Safari (1, 2 and 3) and Google Chrome.

No, all popular browsers support compression out of the box. Your users will not have to change anything. Older client browsers will not require special treatment since IISxpress recognises them and does not send them compressed responses.

Yes, essentially IISxpress does not care if the content of the response is static or dynamic. If, however the response already has transfer encoding or content encoding IISxpress will not attempt compression. If you are not sure look in the IISxpress Status window's 'History' tab while you are running a browser session to see what is going on.

We recommend that you switch off the build in IIS compression. The IISxpress installer will do this for you.

Yes, but you need to know what mode IIS is running in first. On 32 bit operating systems you should only install the 32 bit version of IISxpress. On 64 bit versions of Windows you need to know which mode your IIS installation is configured to use. If it is running in 32 bit mode then you should use the 32 bit version of IISxpress, if it is running in 64 bit mode then you should install the 64 bit version. If you change the 'bitness' of your IIS installation after installing IISxpress then you will need to uninstall IISxpress and install the other version for it to function properly again.

In general text files compress best since they repeat the same information over and over allowing the compression algorithm the greatest gains. Fortunately HTML and associated web site files fall into this category, so in general there are good gains to be had. Image files with JPG, GIF, PNG, etc. extensions are already compressed so there is no gain in compressing them again. Also MP3 audio and MPEG video files will not compress well for the same reason.

Starting with version 2.1 IISxpress will cache compressed responses. Only static content will be cached, this includes HTML, text, CSS, JS and many other static file types. Responses created dynamically, for example by ASP.NET, ASP and CGI, will not be cached.

The IISxpress Status window is the place to see what IISxpress is doing. Here you can see the overall compression ratio, the individual file compression histories, the recent CPU usage and also configure IISxpress. IISxpress also maintains a set of performance counters which you can access via the standard Windows Performance Monitor tool. To open the tool from the Windows run dialog (or a command prompt) type perfmon. Now click the + button on the toolbar (or press ctrl-i) and then select the IISxpress counter set from the list. IISxpress maintains a comprehensive set of counters you can use the monitor the performance of your web site.

Yes, IISxpress defaults to compressing everything, so you have to exclude the URIs you don't want. This is done via the IISxpress Status window, select 'Exclusions' and then 'URIs'. Select the '/' item in the control, right click and select 'Branch' from the menu. All the items in the tree should now show in red, this means they are excluded.

The 'System' tab of the IISxpress Status window shows the amount of memory used by both IISxpress and IIS.

The 'System' tab of the IISxpress Status window shows the amount of CPU used by both IISxpress and IIS.

Hopefully you won't have to worry much about configuration unless you run into problems. The most likely issue you will encounter is browsers not supporting a certain response type with compression enabled. A common problem area is compressed PDF (Adobe) file responses, the default for IISxpress is to not compress PDF files. This is a problem with the browser and not IISxpress. Under these circumstances you can exclude the file by extension, content (MIME) type or by excluding the URI where it is located. When the file is excluded IISxpress will no longer compress it.

IISxpress supports excluding a file by extension, content (MIME) type or URI. For example to exclude all ZIP files from being compressed add ZIP to the excluded extensions list on the 'Exclusions' tab in the IISxpress Status window.

IISxpress will not compress a file if its extension, content (MIME) type or URI matches one of it's exclusion rules. IISxpress also knows which files did not compress well the last time it attempted to compress them, in this case IISxpress will not attempt to compress them again unless the file has changed.

Sometimes browsers do not handle compressed responses properly, one example is PDF (Adobe) files. Most browsers simply hand the compressed response to the PDF plug-in they are configured to use. The plug-in cannot handle the response correctly resulting in a lock up. Under these circumstances it is best to exclude the file type from being compressed.

Display the IISxpress Status window, if IISxpress is compressing responses you will see the results here.

It's difficult to say what the problem could be. The first place to start tracking the problem down is to disable the IISxpress filter. To do this open the IISxpress status window, select the 'Configuration' tab and uncheck the 'Allow filter to process responses option'. When unchecked IISxpress will NOT intercept the responses. If the problem persists then IISxpress is not the problem. However if this solves the problem then there may be an issue with your configuration. If you need any further assistance please contact our support team at support@ripcordsoftware.com.

IISxpress can be uninstalled via 'Add or remove programs' in the Windows Control Panel.

IISxpress stores its configuration in a file called IISxpress.config which will be located in your 'Program Files\Ripcord Software\IISxpress' folder. Simply copy this file to a safe place. If you want to restore this backup file you need to stop the IISxpress Server process. Open the IISxpress Status window, select the 'Configuration' tab and press the Stop button at the bottom of the window. Remember to start IISxpress once you have copied the file back.

The default setting for IISxpress is to not compresses responses destined for the local computer. This is to reduce the CPU load since compression will actually slow down local access rather than speed it up. If you wish to test your compression configuration you may wish to allow compression for the local computer. To do this open the IISxpress Status Window, select the Exclusions tab and then select the Networks item on the left of the window. You should now remove the check on the 'Exclude compression requests from the local computer option'. The new setting will be applied immediately.

Yes. IISxpress supports the Default, Best Speed and Best Size modes. The compression mode can be changed on the Configuration tab of the IISxpress Status Window.

Currently IISxpress does not support this configuration. Future versions may include this feature.

IISxpress partitions compression requests on a core by core basis. This allows IISxpress to serve the greatest number of simultaneous requests keeping your web site running smoothly. In the Configuration/Advanced tab of the IISxpress you can control core affinity. Basically you can specify which cores are used for compression and which should be excluded. This allows you to reserve cores for specific system processes like a SQL database, ASP.NET, etc.