TreeSize Professional is not available for Mac but there are plenty of alternatives that runs on macOS with similar functionality. The most popular Mac alternative is 
DaisyDisk. It's not free, so if you're looking for a free alternative, you could try 
ncdu or 
JDiskReport. If that doesn't suit you, our users have ranked more than 50 alternatives to TreeSize Professional and many of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to TreeSize Professional are 
GrandPerspective (Free Personal, Open Source), 
QDirStat (Free, Open Source), 
OmniDiskSweeper (Free) and 
DiskWave (Free).
The powerful disk space management software If you're looking for more info about TreeSize Professional like screenshots, reviews and comments you should visit our info page about it. Below you find the best alternatives.
With DaisyDisk you can free up disk space by quickly finding and deleting big, useless files. The program scans any mounted disk and displays it on the sunburst map, where segments mean files and folders, proportionally to their sizes. The map is easy to read and navigate. You can also quickly preview any file and reveal it in Finder to delete.
A disk usage analyzer with an ncurses interface, aimed to be run on a remote server where you don't have an entire gaphical setup, but have to do with a simple SSH connection. ncdu aims to be fast, simple and easy to use, and should be able to run in any minimal POSIX-like environment with ncurses installed.
JDiskReport enables you to understand how much space the files and directories consume on your disk drives, and it helps you find obsolete files and folders. The tool analyses your disk drives and collects several statistics which you can view as overview charts and details tables. This is ad-free uncrippled no-charge binary multi-platform software that never expires.
GrandPerspective is a small utility application for Mac OS X that graphically shows the disk usage within a file system. It can help you to manage your disk, as you can easily spot which files and folders take up the most space. It uses a so called tree map for visualisation. Each file is shown as a rectangle with an area proportional to the files size. Files in the same folder appear together, but their placement is otherwise arbitrary.
QDirStat is a graphical application to show where your disk space has gone and to help you to clean it up. From the author of the original KDirStat. This is a Qt-only port of the old Qt3/KDE3-based one, now based on the latest Qt 5. It does not need any KDE libs or infrastructure. It runs on every X11-based desktop on Linux, BSD and other Unix-like systems. QDirStat features both tree and treemap which makes easier to identify disk usage.
OmniDiskSweeper is a Mac OS X utility for quickly finding and deleting big, useless files and making space on your hard disks. OmniDiskSweeper scans your disks and highlights the biggest files, so you can determine what's using up your disk space. It's a fast, easy way to find things that are hogging your drive and clear them out so you've got room for the stuff you really need. Key Features 1.
DiskWave is a free utility to help you determine where most of your hard drive space is consumed. The program scans your hard drive to compute the size of all folders and sub folders. The results are stored in memory, which allows faster navigation than the built-in “compute all sizes” option in the Finder. You can easily identify useless directories and delete them.
Disk Usage Reports is a web-based way to view disk usage on remote computers or servers, or to provide usage reports to users who store files on your server. Reports are stored as static files which are retrieved via AJAX. No database is required.
Free open-source cross-platform file & directory statistics as found on Github - Generate a directory tree for any given folder - View any folder as colored rectangles (squarified algorithm) - Customize the rectangle colors and show statistics about filetypes - Export the tree as JSON with sizes and file/folder counters - Export the rectangle view as JSON, SVG or PNG - Easy start screen with sane default settings
Duc is a collection of tools for inspecting and visualizing disk usage. Duc scales quite well, it has been tested on systems with more than 500 million files and several petabytes of storage.
