The most-asked question about any third-party Windows utility — and one with a clear, verifiable answer. The app is MIT-licensed open-source, every line readable on GitHub, no registry edits, no telemetry, no network calls. This page documents exactly why and how. Source by builtbybel.
PC cleaning software has earned a poor reputation over twenty years. Fake performance scores, registry "fixes" that break Windows, telemetry pipelines, bundled adware — the category is full of red flags. This page exists to document, point by point, why this particular open-source cleaner does not share those problems.
Three architectural decisions make the safety question answerable: the app skips registry cleaning entirely (no risky deletes), it makes zero outbound network calls (no telemetry, no analytics, no licence checks), and the entire source is published on GitHub under MIT licence (anyone can audit). Together those mean the answer to "is fluentcleaner safe" is verifiable, not just a marketing claim.
The safety case rests on architecture, not marketing — every claim below is provable by reading the source code or running a network monitor.
The app intentionally skips registry cleaning. Registry "cleaners" delete orphaned keys with little benefit and significant risk. This cleaner refuses the entire risky category by design.
No telemetry pipeline, no analytics endpoint, no licence-validation server, no crash reporter. Run any network monitor while the app is scanning — outbound traffic is zero.
Every line of code is on GitHub under MIT licence. No obfuscated binaries, no hidden helper services, no closed components. Read it before you run it.
Nothing is removed without your review. The scan results show every file path and category before you click Clean — opt out of anything that looks unexpected.
The download installs only the cleaner. No browser toolbars, no PC optimiser sidecars, no trial of unrelated software bundled into the installer.
Open the builtbybel repo — every file is visible. Look for network calls, registry writes, telemetry endpoints. You will not find any.
Use Process Monitor or Wireshark while the app scans. Outbound network traffic should be exactly zero.
After install, run a scan and inspect every file path before clicking Clean. Nothing is removed without your explicit approval.
Open-source under MIT licence by builtbybel. Read the code, run the scan, see for yourself.