Date: 2026-08-10 · Machine: the developer's own daily-driver workstation (Windows 11 Pro, heavily used dev machine — your numbers will be smaller on a lightly-used PC) · Method: everything below was measured, not quoted from marketing. Scripts and raw snapshots are kept and the test is reproducible; claims about other products appear here only because we hold the evidence for each one.
A note on spirit: this is not a takedown. CCleaner and Storage Sense are tools with different design goals. This document exists because our README makes comparative claims, and claims require a protocol.
Method: a read-only script enumerated (a) every location Temp Cleaner
finds with its default 7-day age limit, and (b) every category Windows
built-in cleanup covers (registry VolumeCaches — 31 categories, all of
them system areas, none targeting third-party application caches). The
script deleted nothing.
Result:
| Locations | Junk (7-day+) | |
|---|---|---|
| Temp Cleaner sees | 440 | 31.3 GB |
| of which Windows built-in tools cover | 3 | 58.5 MB (= 0.2 %) |
The remaining 99.8 % — browser caches, Electron apps, package managers, sync clients — is invisible to the built-in tools. Top three finds on this machine: a package manager cache (11.4 GB), a Store-container mirror of the same cache (10.5 GB), a sync client's temp (6.6 GB).
Bonus finding: Storage Sense was enabled on this machine, but its
schedule was the default "run only during low free disk space" (registry
value 2048 = 0). In practice "Windows cleans automatically" often means
"not until the disk is nearly full".
Method: official installer (ccsetup641.exe, 84.3 MB, Authenticode
valid, Gen Digital Inc.), silent install, registry snapshots taken
before install, after install, and after uninstall, then compared.
What we confirmed in CCleaner's favour (our own README table had to be corrected — it was unfair to the competitor before this test):
- Analyze IS a real preview — 10.04 GB found in 4.6 s, categories with sizes and file counts, "No files deleted yet". Our table now says "✅ Analyze".
- It is faster than us: 4.6 s for its fixed list vs our 93 s full walk (which found 31.3 GB). A flashlight is faster than exploring the jungle; we simply cover different ground.
What the audit found on the other side:
- No age filter (our slider has no equivalent), no explanation of what was skipped or why, granularity is categories — not concrete folders you can open and inspect.
- Default checkboxes come pre-enabled for Empty Recycle Bin, Cookies and Memory Dumps — one "Run Cleaner" click executes all of that at once.
- Install footprint: two scheduled tasks created immediately
(
CCleanerCrashReporting,CCleanerSkipUAC), plus the usual registry presence and in-app upgrade/updater promotions. - After uninstall: the visible Piriform keys were removed cleanly,
but two hidden GUID-named registry keys remained (in
HKLM\SOFTWARE\andHKLM\SOFTWARE\Classes\), both containing a machine ID and a DPAPI-encrypted blob, plus two orphaned CLSID entries. They resisted normal deletion and required elevatedreg delete /f.
Temp Cleaner's footprint, same protocol: zero registry keys, zero
scheduled tasks, zero services — delete the exe (and its
%LOCALAPPDATA%\TempCleaner folder, which the app itself removes when
you switch to portable mode) and nothing is left.
Recycle Bin, Windows Update leftovers / WinSxS, Previous installations — the built-in tools clean these and Temp Cleaner never will, by design: Windows knows its own internals better than any third-party tool, and our "nothing is lost" promise does not mix with system-area deletion. Temp Cleaner is a companion to the built-in tools, not their replacement.
Protocol artifacts (scripts, registry snapshots, raw JSON) are archived in the project's tooling folder. If you want to reproduce Part 1 on your machine — ask the author at claude.ai with this repository's link; the script is read-only and safe to share.