Enable Gzip compression in IIS 6.0 for ASP.NET 2.0 websites

Introduction

This step by step guide will show you how to enable Gzip compression to work with ASP.NET 2.0. Compressing the output should make your websites faster, especially when being viewed via a slow connection.

Step 1: Enable Compression Using the IIS Manager

Expand IIS Manager. Right click on Websites. Click Properties. Click the Service tab. Check the boxes to enable compression.

Step 2: Install IIS 6.0 Resource Kit Tools

You can download the free tool from Microsoft here.

Step 3: Edit IIS Meta Database

Open the IIS Metabase Explorer. It is part of the resource kit you just installed. Expand LM>W3SVC>Filters>Compression. You will need to edit both gzip and deflate. Find the item with the name HcScriptFileExtensions. Add the values aspx, axd, asmx, and css. Repeat process for gzip and deflate. Find HcDynamicCompressionLevel and set it to something higher than 0.

Step 3: Do IISReset

That's it. To verify that you have everything working correctly, you can use the free tool YSlow for Fire Bug.