What is fluentcleaner?

FluentCleaner is a free, open-source Windows disk cleaning app built with WinUI 3, Microsoft's modern desktop UI framework, for Windows 10 and Windows 11. It is inspired by the original CCleaner from the mid-2000s, before that tool acquired a reputation for dark patterns and upselling, and aims to do what a cleaner should: remove temporary files, browser data, app caches, and leftover traces from uninstalled software, without anything deceptive. The key differentiator is that it uses winapp2.ini, a community-maintained database of cleaning rules built up over 15+ years with thousands of entries covering specific apps. Each entry precisely targets known cache folders, temp paths, or registry keys for a given app, rather than using broad wildcard deletions. You can use the default database, point to a custom one from another source, or build your own and load it via Settings. Beyond standard cleaning, it supports running silently from the command line (useful for automation via Windows Task Scheduler) with a /AUTO flag, and optionally shuts the system down after cleaning finishes. Each automated run creates a detailed log showing what was deleted and how much space was recovered. The app is a solo project, written in C#. It supports Windows 10 build 19041 and later as well as Windows 11. You would reach for it if you want a straightforward, auditable cleaner without ads, registry tricks, or scare prompts, and you want full control over which rules apply. The full README is longer than what was provided.