OmniDiskSweeper vs TreeSize

OmniDiskSweeper is a free macOS utility that displays files on a drive from largest to smallest. This ordering helps users locate large unwanted files, open them, or remove them. Moving items to the Trash is the default action; holding the Option key enables direct deletion instead. The utility can scan external drives. Omni says the version compatible with macOS 26 makes the entire app accessible with VoiceOver, and the product page lists older downloads for macOS 10.4 through 10.13. The freeware download requires no form or personal information. Omni says it does not share data gathered from its apps or websites with social media or advertising services. Support is available by email and phone Monday through Friday, 10am–5pm Pacific Time. The company notes that OmniDiskSweeper is updated less frequently than its other titles, although it still receives updates. The Omni Group is employee-owned and based in Seattle, Washington.

TreeSize analyzes files and folders to show how storage is used on Windows desktop systems. Scans can cover local drives, network shares, cloud storage, USB drives, SD cards, and external hard drives; treemap views and file-type breakdowns help present the results. Depending on edition, results can be exported to PDF, Excel, CSV, HTML, or SQLite. Professional adds server scanning, command-line parameters, scheduled scans, and automated reporting. Other listed tools include deleting, moving, bulk renaming, archiving, duplicate finding, and deduplication. TreeSize Free is for private, non-commercial use on Windows desktop and cannot be used on Windows Servers. The editions run on Windows Desktop and operate on-premise; the maker says data does not leave the computer or site and is not shared with third parties. Personal and Professional have 14-day free trials, while SpaceObServer Enterprise has a 45-day trial. Annual prices listed include 20.40 € per user for Personal and from 40.80 € per user for Professional. The Free plan is listed at free.