TreeSize Free Portable lets you scan directory size and find the space hogs to free up space on your drive. TreeSize Free Portable can be started from the context menu of a folder or drive and shows you the size of this folder, including its subfolders. You can expand this folder in Explorer-like style and you will see the size of every subfolder. All results can also be drilled down to the file level. Scanning is done in a thread, so you can already see results while TreeSize Free is working. TreeSize Free Portable can display the NTFS compression rate and apply the NTFS compression on directory branches.