How it works

Snapshots, then differences

That's genuinely the whole idea. DiskSpace measures your folders on a schedule, remembers the measurements, and shows you the difference between any two of them.

Why nobody else does this A one-off scan can't tell you what changed, because it has nothing to compare against. Answering “what grew?” requires having measured before the growth happened — which means the tool must have been running all along. DiskSpace is built to run all along.

Keep reading

Three steps, then it's automatic

Set-up takes about a minute. After that you never think about it until you need it.

Install and pick your drives

Install from the Microsoft Store, choose which drives to watch (usually just C:), and DiskSpace takes its first measurement. No administrator prompt — it runs as a normal user.

It measures in the background

Every few hours DiskSpace re-measures your folders at low I/O priority and stores the result. It skips battery-saver mode and full-screen apps, so you'll never notice it running.

Ask “what changed?”

When your free space drops, open DiskSpace, pick a time range, and read the answer: which folders grew, by how much, and what category they belong to. Then go fix it.

One honest caveat DiskSpace can only tell you about changes it was around to see. The day you install it, your history is one point long. Give it a few days and it becomes genuinely useful — which is exactly why it's worth installing before you have a problem.

Under the hood

For the people who want to know what a background disk tool is actually doing.

1

It records folder totals, not every file

Each snapshot stores per-folder totals — size, size-on-disk and file count. Storing every filename on every scan would produce a multi-gigabyte database and make DiskSpace the disk problem. Folder totals answer the question at a fraction of the cost.

2

Only changes are written

A new snapshot only stores folders whose numbers actually moved. On a typical PC that's a tiny fraction of the tree, which keeps the database small and daily disk writes low — important on SSDs.

3

It never asks for administrator rights

DiskSpace runs as a standard user. Folders Windows won't let a normal program read are counted as inaccessible rather than triggering an elevation prompt. A tool that watches your disk shouldn't demand the keys to the machine.

4

It won't download your cloud files

OneDrive files that live in the cloud are recognised by their attributes and measured without ever being opened — so scanning never triggers a download or eats your data cap. Junctions and symlinks are detected and never followed in circles.

How far back you can look

Recent detail stays fine-grained; older history is thinned to one point per day.

How old	Detail kept	Free	Premium
Last 48 hours	Every snapshot (about 4 per day)	✓	✓
2 – 3 days	One snapshot per day	✓	✓
7 – 60 days	One snapshot per day	—	✓
Older than 60 days	Removed automatically	—	—

Upgrading is instant, not forward-looking DiskSpace quietly keeps a little history beyond the free window. When you buy Premium, that history appears immediately — you don't start from zero and wait weeks for your timeline to fill in.

See pricing Read the FAQ