Fathom

See folder sizes in Google Drive and find what is actually using your storage. No login, zero setup, runs on-device.

Google Drive shows you the size of individual files, but never the size of a folder. When you run out of storage there is no built-in way to find out which folder is responsible. Fathom answers that. Open Drive, click scan, and see every folder and file ranked by how much space it is using. NO SETUP There is no account to create and nothing to sign in to. Fathom reads your Drive through the Google session already open in your browser tab. WHAT IT DOES • Scan a single folder, your whole Drive, or everything shared with you • Folder sizes calculated recursively, largest first • Click any result to jump to it in Drive. Fathom opens the containing folder and highlights the item — it never opens the file itself • Export results to CSV or JSON so you can check the numbers yourself • Results are saved, so closing the panel does not lose your scan HONEST ABOUT NUMBERS Storage figures are easy to get subtly wrong, so Fathom shows its working: • A file whose size Google does not report is labelled "not reported" rather than shown as 0 bytes • Shortcuts count as zero, so the file they point at is not counted twice • Trashed items are excluded by default but reported separately, because they still use your quota • Where the total cannot match Google's own figure — revision history, Gmail and Google Photos share the same quota — the difference is explained on screen PRIVACY Fathom reads file and folder metadata only: names, sizes, dates, owners and folder structure. It has no permission to read the contents of your files. Scan results are stored on your own computer and nowhere else. There is no server, no account, no analytics and no crash reporting. Nothing you scan is ever transmitted anywhere. Settings has a button that deletes everything Fathom has stored. Fathom is open source and is not affiliated with, endorsed by, or sponsored by Google. Google Drive is a trademark of Google LLC.