Folder Size Analyzer

Why you cannot see folder sizes where you need them

Google Drive lists the size of each file but never the total of a folder, Windows Explorer shows a folder's size only one folder at a time in its Properties dialog, and the macOS Finder leaves the column blank unless you ask it to calculate. When the disk or the storage quota is full, the question is always the same — which folder is it? — and the usual answer is to install a disk analyser. This page answers it in the browser: every folder is added up at once and sorted largest first, and the largest files and file types are listed beside it.

What the page reads, and what it does not

When you choose a folder, the browser hands the page a list of the files in it with each one's name, path, size and date of last change. That is all this page uses. No file is opened, so a folder of several hundred gigabytes is added up in seconds, and nothing is sent anywhere: the page's security policy does not allow it to contact any other site. Chrome and Edge ask "Upload N files to this site?" before they hand the list over; that is the browser's standard wording for any folder picker, and on this page nothing is uploaded.

Getting the sizes of a Google Drive, OneDrive or Dropbox folder

Install the provider's desktop app (Google Drive for desktop, OneDrive, Dropbox) and choose the synced folder here, for example the G: drive's My Drive. The sizes come from the file system, so files that are kept online only are normally counted at their full size without being downloaded. Google Docs, Sheets and Slides count as almost nothing, because they do not use storage quota and appear on disk only as small link files. Files shared with you and the bin are not in the synced folder; Google counts the bin against your quota, so empty it when the totals here do not add up to the quota you see.

Why the total differs from the disk's "used" figure

• Units. Windows calls 1,048,576 bytes a megabyte, macOS and most Linux file managers call 1,000,000 bytes one. Switch the units above to match the system you are comparing with; the difference is 7% at the gigabyte scale.
• Size on disk. Files take up whole blocks, usually 4 KB, so a folder of many tiny files uses more space than the sum of their sizes. This page adds up the sizes.
• What the browser leaves out. Folders the browser is not allowed to read (system folders on Windows and macOS) are refused when you choose them, and a folder picker does not list empty folders.

Frequently asked questions