I have been using OmniDiskSweeper to reclaim disk space ever since it debuted alongside the arrival of Mac OS X.. OmniDiskSweeper only does one thing. It scans your disks and highlights the largest files, so you can determine what’s using up your disk space. Once you have located an undesirable large file or directory OmniDiskSweeper’s built-in delete button destroys the offending data permanently without stopping at the trash. It can even eliminate smaller files too. If you know how to use the Finder’s column view then you know how to use OmniDiskSweeper. It has never let me down.

Since moving exclusively to high-bandwidth, low-capacity SSDs storage has become a premium on my computers. OmniDiskSweeper’s simple approach to data visualization still works in Lion, but the program has not seen a meaningful update since its debut in 2001. Continuing to use the tool that works may be what Minimal Mac believes in, but as a technology enthusiast I am always looking for the next best app, preferably with a gorgeous 512 by 512 icon.

I fist heard about DaisyDisk from Daring Fireball, but immediately wrote it off it as one of those sloppy data visualization apps that displays your files as a picture with little or no intelligence. My assumptions couldn’t have been further from the truth. DaisyDisk is more than just a pretty picture. It combines OmniDiskSweeper’s tried and true sort-by-size approach with an intelligent infographic that shows you the contents of your disk faster than any hierarchical list ever could.

Upon launching DaisyDisk you are greeted with a stylized window that lists your computer’s local volumes alphabetically. DaisyDisk’s interface doesn’t come out and say it, but its “Scan Folder‚” button can also be used to scan network volumes too. Next to each local volume is a simple bar graph depicting the amount of free space available. Specific folders can be dragged into the DaisyDisk window and bookmarked for easy access. No where in DaisyDisk’s interface is there an extraneous control, or out of place preference. Just like OmniDiskSweeper DaisyDisk does one thing, and one thing well, and that is scanning your disks for large files.

I was amazed how fast DaisyDisk scanned my Users volume. OmniDiskSweeper takes time to scan each directory, but Daisy shot through my filesystem in seconds, exploding into a star of color the moment it was done. It can even scan multiple volumes in parallel, detecting SSDs correctly so as not to impede their performance. Instead of just showing blocks on a grid, or entries on a list, DaisyDisk’s infographic shines out like the rays of a sun. This kind of data representation is called a sunburst, and although DaisyDisk was not the first to use it they have improved upon the original concept making navigation easier. The larger files take up the most space, but their position from the center designates their order in the filesystem. Instead of starting at the root like most data visualization apps Daisy Disk brings the far out files forward immediately displaying what’s consuming the most of your drive space.

You can click on any folder and DaisyDisk’s sunburst will be rendered around that directory with its root as the core. Clicking the core moves you backwards through the file structure towards the root of your drive. Hitting spacebar on any section gives you a Quicklook preview. Accompanying every DaisyDisk sunburst is a hierarchical list of the selected directory’s contents organized by size. Each list item can also be previewed with Quicklook or used for navigation. Additional navigational buttons can be found along the top of the DaisyDisk window as well as an interactive trail of breadcrumbs. The bottom of the DaisyDisk window displays a home button, and DaisyDisk’s most innovative feature “the collector.”

Just as with a real flower, you can tear off petals from DaisyDisk’s sunburst and drop them into a special area called “The Collector.” The Collector collects files and directories you wish to delete until you are ready to delete them. You can expand the Collector by clicking on it to make sure you are not about to accidentally delete the wrong files. The expanded Collector works just like the hierarchical list, so you can preview files and drag them out as needed. DaisyDisk’s intelligence extends into which files you can delete and which you cannot. The Collector will not accept petals that cannot be removed like /System, /Library or the current user’s home folder. Clicking the Delete button starts the deletion process, but don’t get scared: you’ll have 5 seconds to change your mind and press Cancel. The whole process feels like the Hollywood inspired launch of a nuclear missile.

DaisyDisk’s single preference offers to congratulate you for deleting more than 5 GBs of files. You can choose to Tweet your drive space recovery like I did.

I've just got an extra 5.2 GB on my disk. That's more disk space than the iPod had in 2001! Thanks to @DaisyDisk

DaisyDisk’s drive space recovery features are just as targeted as OmniDiskSweeper’s, but its has the performance and polish to make it irresistible. With DaisyDisk I am able to identify large files faster, and its intuitive to navigate sunbursts will keep me coming back far more often than any hierarchical list ever would. At 50% off, $9.99 is a value for this app, and I encourage you to buy it before the sale ends.