For Windows 10 and 11
Measured,
not claimed.
See every file on your disk, and what removing it really gives back.
Nothing is deleted unless you ask for it by name. What you select is moved aside with a manifest, and one button puts it back.
Steam creates its download targets at full size before writing a byte into them. Every cleaner that sums file sizes promises you the first number.
The error
The number every cleaner shows you is not the one you get back.
It sums file sizes and calls that your saving. That is not what the volume gives back, and the gap is not small.
| Directory | Summing file sizes claims | Deleting it actually returned |
|---|---|---|
| Steam download staging | 61.4 GB | 22.1 GB |
Unity Library caches, 24 backups |
93.3 GB | 95.3 GB |
The first is sparse preallocation. The second is cluster slack, hundreds of thousands of tiny files each rounding up to the next cluster. The error runs in both directions, which is why you cannot correct for it by being suspicious of large numbers.
Reclaim measures allocated size, per file, and where the two differ meaningfully it shows the gap so you can see what you were about to be promised.
The four tiers
“Is this safe to delete?” is the wrong question.
Almost everything technically is. The question that decides anything is what it costs you to get it back, and that ranges from nothing at all to gone for good.
Nothing references it. Removing it costs nothing at all.
Temp files, crash dumps, finished update payloads, interrupted downloads.
Restored by recomputing it. Costs CPU time, sometimes a lot.
Package manager caches, shader caches, browser caches, build output.
Not reproducible. Never selected for you.
Old disc images, downloaded installers, backup copies, exports, mods.
The default, and where anything unrecognised lands.
System files, projects, saves, credentials, installed software.
Every byte falls into exactly one of these, so the four add up to the whole disk rather than to a list of interesting places.
Anything no rule recognises is Leave alone. A classifier that guesses “probably junk” about unfamiliar paths eventually meets somebody's irreplaceable folder and is confidently wrong about it. Being useless about an unknown directory costs nothing. Being wrong costs everything.
The same folder can land in different tiers depending on where it sits. A Unity
Library in the project you are working on costs a full reimport to
rebuild. The byte-identical folder inside a dated backup costs nothing, because
that rebuild only ever happens if you open that backup again.
Evidence
It proves rather than pattern matches.
A directory is only claimed when its ecosystem's marker sits beside it. These two
are both called Library, and only one of them is a cache.
And it refuses rather than guesses. If a detector cannot gather complete information it aborts and says so, instead of returning a partial answer. That matters most in the Windows Installer cache, where a package is proven unreferenced by reading the registry: if any branch of that registry is unreadable, every package it referenced would look orphaned. Reporting those as garbage would break nothing today, which is the worst part, because the damage only surfaces months later when a repair asks for an installation source that no longer exists.
The scan
It maps the whole disk, not just what it recognised.
The NTFS file table is read directly where the volume allows it, which turns a multi-minute tree walk into seconds.
to read 2.7 million records from the file table on a real drive
for the equivalent directory walk on the same drive
network request the program makes, and it is the update check
Run it as administrator if you can. Without those rights it cannot open the file table and falls back to walking directories: identical numbers, minutes instead of seconds. The application says which of the two produced what you are looking at.
What it finds
Named individually, never swept by pattern.
-
Windows Installer
Orphaned
.msiand.msppackages inC:\Windows\Installer, proven unreferenced against the installer registry. Neither Disk Cleanup nor Storage Sense touches this directory. -
Build output
node_modules, Rusttarget, UnityLibrary, Python virtualenvs,__pycache__,.next— each claimed only when its marker file sits beside it. - Package caches npm, pip, Yarn, Gradle, NuGet, Cargo, Unreal's derived data store, NVIDIA shader and driver caches.
-
Games
Steam download and workshop staging, plus
commonfolders left behind by uninstalled games. Leftovers holding hand-written server configs are flagged as yours and never preselected. -
System
Temp directories, the Windows Update download cache,
Windows.old, Recycle Bins.
Every finding explains itself. Expand a row and it says what the evidence is and what the removal costs, in plain words. A cleaner that cannot say why it wants to delete something is a cleaner you should not trust.
Undo
Quarantine is the default, not a setting.
Selected items are moved aside on the same volume, which makes it a rename rather than a copy, and a manifest is written next to them recording where each one came from.
Restoring is a button in the application, and the manifest is plain JSON in
<drive>\.reclaim-quarantine\ so you can always do it by hand.
Permanent deletion exists, and you have to ask for it by name.
Download
Windows 10 or 11, x64. Free for personal use.
Portable ZIP
Unpack it and run reclaim.exe. Nothing is installed, nothing
touches the registry, and deleting the folder removes every trace. Take this
one if you would rather not let an unfamiliar program install itself before you
have decided whether you trust it.
MSI installer
An ordinary Windows install with a Start menu entry. It installs for all users, so Windows asks for administrator rights during setup. It is also the only one of the two that can update itself.
Windows will warn you
SmartScreen will say the publisher is unrecognised. That is true, and it is about the absence of a code signing certificate rather than about anything found inside the file. Click More info, then Run anyway. Every release lists SHA-256 hashes if you would rather check first.
This is early. v0.1 is Windows only and does the scan, quarantine and restore loop. It has been used to clear a little under 600 GB from one real machine, which is exactly one machine, so treat a surprising result as worth reporting rather than as gospel — particularly a case where Reclaim's number disagreed with what your disk actually did. Open an issue; the useful ones say which drive, what Reclaim claimed, and what actually happened. A rule that classifies something wrongly is worth reporting even when nothing was deleted, because the classification decides what gets offered in the first place.