Space Survey · Windows and Mac computers
See what is filling the drive.
Point the Folder Scan at a folder and read it like a core sample: video, photos, installers, mail data, layer by layer. Then log the free space now and then, and the Space Logbook tells you when the drive will be full.
- Nothing is uploaded. The scan runs in this browser tab.
- No account, no email. The logbook opens with a private link.
- Survey Pass $1.95 a month or $19.50 a year; free during preview.
Three instruments
Measure, forecast, keep the record.
-
01
Folder Scan
Space by kind of file, the biggest folders (click to dig down), the largest files, big files nobody has touched in two years, likely duplicates and a cleanup list. Suggestions only: the site deletes nothing.
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02
Fill Date
Three numbers from This PC or Storage settings today, and one from a while back: how fast the drive is filling, and the day it reaches 10% free and full.
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03
Space Logbook
Keep free-space readings and scan totals for each drive, see the trend drawn, and compare two scans to find what grew. Private link, no account.
How the scan stays private
The scan never leaves this tab.
Your browser hands the page the names, sizes and dates of the files in the folder you pick. The page adds them up right there. No file, name or path is sent to us.
You can check it yourself: open the Folder Scan, disconnect from the internet, then scan. It still works.
Only if you press Save to my logbook does anything travel: the totals you see on screen first (per kind, and the top-level folders, with their names only if you keep them). Never a file name.
Worked example
A 512 GB laptop, read on the first of each month.
| Reading | Free | Used |
|---|---|---|
| Jun 1, 2026 | 120.4 GB | 356 GB |
| Jul 1, 2026 | 101.2 GB | 376 GB |
| Aug 1, 2026 | 84.9 GB | 392 GB |
| Sep 1, 2026 | 66.3 GB | 411 GB |
Full around December 24, 2026 at about 17.7 GB a month.
- Used now
- 411 GB
- Free now
- 66.3 GB
- Change in used space
- +17.7 GB a month
- Under 10% free
- Oct 4, 2026 (33 days)
- Full
- Dec 24, 2026 (114 days)
From 4 readings over 92 days (Jun 1, 2026 to Sep 1, 2026). A straight-line trend: a big download, a new game or a cleanup moves the date, so log a reading now and then.
Survey fees
Free to measure. $1.95 a month to keep the record.
Free
$0
Folder Scan up to 25,000 files, Fill Date, a logbook for 1 drive with 6 readings.
Survey Pass, monthly
$1.95a month
Cancel any time in PayPal; the Pass runs to the end of the month you paid for.
Survey Pass, yearly
$19.50a year
Two months free against paying monthly ($23.40).
Preview: these are the real prices. Free during preview. Nothing is charged, and there is no checkout yet: every Pass feature below is switched on for everyone until payments open.
| Instrument | Free | Survey Pass |
|---|---|---|
| Folder Scan: space by kind, biggest folders, largest files, untouched files, cleanup list | Yes | Yes |
| Files read in one scan | 25,000 | 400,000 |
| Likely duplicates (same name and size) | Yes | Yes |
| Duplicates confirmed by content (SHA-256, in your browser) | - | Yes |
| Fill Date calculator | Yes | Yes |
| Drives in your Space Logbook | 1 | 5 |
| Readings kept per drive | 6 | 120 |
| Compare any two scans of a drive | - | Yes |
| Printable survey report and CSV download | - | Yes |
Field notes
Before you scan
Will it delete or move anything?
No. The page can only read names, sizes and dates; it has no way to change your files. The cleanup list is a set of suggestions for you to check in File Explorer or Finder.
Why does my browser say "upload"?
Some browsers (Firefox and Safari among them) let a page read a folder only through their folder-upload picker, so the button or prompt may say "upload". Nothing is sent: the page reads the list inside the tab. Chrome and Edge use a newer picker that asks whether to let the site view the files instead.
Can I scan the whole C: drive?
Browsers refuse a whole drive and system folders on purpose. Scan the folders that hold your own files: your user folder's Documents, Downloads, Pictures, Videos, Desktop, or a folder on a second drive. For the drive as a whole, the Fill Date and the logbook use the free-space figure Windows or macOS shows you.
Does it use AI?
No. Everything is plain arithmetic on the numbers you see.