FolderSizes v4.1 and the File Extension Researcher

Today we’re releasing FolderSizes v4.1, an update with a sprinkling of new feature goodness and numerous performance optimizations. There are also a few minor bug fixes thrown in for good measure.

One of the new v4.1 features is something that I’ve actually been thinking about for a while now – a File Extension Researcher tool. As you’re probably aware, there is no central authority for file extensions, and it can sometimes be difficult to track down the source of file extensions that you encounter. Well, the FolderSizes v4.1 File Extension Researcher is designed to help.

As you can see from the first screen shot, the File Extension Researcher allows you to enter a file extension (e.g. “.pdf”, “.dat”, etc.) and provides two pieces of information in return. First, it shows the Windows shell file association, which largely controls how Windows itself responds to the extension. But for many extensions, Windows has no shell association whatsoever, and the second piece of information – a general listing of potential application matches – can help in those cases.

Additionally, you can click the Research Online button, which will launch your default web browser and pull up additional details on the extension in question. Currently, the source for this additional information is – an excellent website dedicated to this task.

You can click the View All Extensions button to see a complete listing of all the file extensions that FolderSizes knows about (over 23 thousand of them!). To keep things manageable, the extension browser window groups the extensions by leading alpha character, number, or symbol.

As an added convenience, the new File Extension Researcher can be launched by right-clicking any file listed anywhere within FolderSizes 4.1 (as long as the file has an extension).

There are lots of other goodies in the new FolderSizes v4.1 release (see release notes on the download page). This just happens to be one of my favorites. 🙂