One of my favorites features in the IIS Search Engine Optimization (SEO) Toolkit is what we called Report Comparison. Report Comparison basically allows you to compare two different versions of the results of crawling the same site to see what changed in between. This is a really convenient way to track not only changes in terms of SEO violations but also to be able to compare any attributes on the pages such as Title, Heading, Description, Links, Violations, etc.
There are a couple of ways to get to this feature.
1) Use the Compare Reports task. While in the Site Analysis Reports listing you can select two reports by using Ctrl+Click, and if both reports are compatible (e.g. they use the same Start URL) the task "Compare Reports" will be shown. Just clicking on that will get you the comparison.
2) Use the Compare to another report menu item. While in the Dashboard view of a Report you can use the "Report->Compare To Another Report" menu item which will show a dialog where you can either select an existing report or even start a new analysis to compare with.
In both cases you will get the Report Comparison Page displaying the results as shown in the next image.
The Report Comparison page includes a couple of "sections" with data. At the very top it includes links showing the Name and the Date when the reports were ran. If you click on them it will open the report directly just as if you had used the Site Analysis report listing view.
The next sections shows a lot of interesting built-in data such as:
Whenever you click the links you get a query dialog that you can customize just as any Query in the Query builder, where you can Add/Remove columns, add filters, etc.
My favorite one is the "Modified URLs" source when you actually can add filters that compare URLs coming from the two different reports.
Note that when you double click or "right-click –> Compare Details" any of the rows you get a side-by-side comparison of everything in the URL:
Again, you can use any of the tabs to see side-by-side things like the Content of the pages or the Links both versions have or the violations, or pretty much everything that you can see for just one.
Finally, you can also right click on the Query dialog and choose "Compare Contents". This will launch whatever File Comparison tool you have configured using the "Edit Feature Settings". In this case I have configured WinDiff.exe which shows something like:
As you can see Report Comparison offers is a powerful feature that allows you to keep track of changes between two different reports. This easily allows you to understand over time how your site has been affected by changes. For Site managers it will allow them to query and maintain a history with all the changes. You can imagine that using an automated build process that runs IIS SEO Toolkit crawling whenever a build is made that keeps the report stored somewhere and potentially annotate it with the build number you could even keep a correlation of changes in code with Web site crawling.