Inspired by the early CCleaner era, FluentCleaner reimagines the classic PC cleanup utility for modern Windows systems. Built with WinUI 3, it focuses on a cleaner, lightweight experience centered around removing temporary files, cache, logs, and leftover clutter - without aggressive registry tweaks, bundled extras, or scareware-style prompts.

The project also embraces the community-driven spirit that helped make older cleanup tools popular in the first place. FluentCleaner supports the well-known winapp2.ini cleaning database format, allowing it to leverage a large ecosystem of community-maintained cleaning rules while keeping the app fast, transparent, and easy to use.

Features

  • Portable design with no installation required
  • One-click system analysis and cleanup
  • Support for optional maintenance extensions
  • Optimized for Windows 11
  • Clear and easy-to-understand cleanup results

System Requirements:

  • Windows 10 2004 (Build 19041) and later
  • Windows 11

No Windows 11 requirement. Despite using WinUI 3, the app is intentionally built to remain compatible with modern Windows 10 systems as well

What's New

FluentCleaner Classic 1.12.125

  • [Improved] Recursive scans now skip fully excluded directory trees instead of scanning and filtering them afterward, making analysis noticeably faster when large folders are excluded (#130)
  • [Added] A comprehensive FluentCleaner Classic User Guide covering first steps, cleaning databases, exclusions, Custom Cleaners, Rule Lab, portable mode, scheduling, localization, safety, troubleshooting, and technical details
  • [Info] Many sections also apply to the Modern edition, as both versions share the same FluentCleaner.Core parser, cleaning engine, Winapp2 databases, and exclusion logic
  • [Added] Optional local supporter recognition. Supporters can add a name or alias and appear as a Classic Supporter in the About page. The status is stored locally in supporter.json, no account, telemetry, or payment verification involved
  • [Improved] FluentCleaner Classic now starts noticeably faster
  • [Improved] Reduced memory usage and improved responsiveness during startup
  • [Added] Settings export and import as portable JSON files directly from the About page
  • [Added] Support for custom OpenAI-compatible providers with an editable API endpoint, model name and API key Discuss here #31
  • [Added] OpenRouter as the preconfigured endpoint for OpenAI-compatible providers
  • [Improved] Imported settings now refresh all existing Options pages before offering a restart
  • [Improved] Portable mode is now clearly shown in green next to the application version
  • [Improved] Streamlined the About page with compact settings backup controls
  • [Improved] Added endpoint and model validation to the AI provider test
  • [Improved] AI response caching now distinguishes between providers, endpoints and models
  • [Improved] Consolidated restart handling for language changes, database updates and imported settings
  • [Refactored] Cleaned up and reorganized AppSettings
  • [Fixed] FluentCleaner Classic now remembers when its window was maximized and restores that state on the next launch (#112)
  • [Added] Spanish localization
  • [Added] French localization

Classic goes further

Classic includes two features currently not available in the WinUI 3 edition

  • Built-in cleaning scheduler: schedule automatic cleaning without messing with Windows Task Scheduler yourself
  • Multi-provider AI Explainer : understand cleaning entries using Groq, OpenAI, or Anthropic
  • Major MainForm, navigation, resource-lifecycle, and settings cleanup makes Classic easier to maintain and extend. Shared cleaning logic remains centralized in FluentCleaner.Core, while the new lightweight localization service handles runtime languages, fallbacks, and translator credits
  • This release also includes several refinements to the WinForms interface
  • Improved behavior on high-DPI displays, including 200% scaling
  • Consistent Segoe UI typography
  • Cleaner analysis summary layout
  • Renamed the main Settings section to Options for clearer navigation
  • Added direct access to the localization folder from the Settings page
  • Added optional translator credits to the About page

FluentCleaner Classic stays lightweight, familiar, and fast, but it is no longer the edition that has to wait for the cool features

  • Fixed a couple of critical DPI scaling bugs #98
  • Running-browser detection, with a warning before cleaning entries tied to a browser that's still open
  • Rule Lab
  • Custom and Settings sections are finalized
  • "Open in folder" on results in the detail view
  • Exclusions
  • Cleaner results display in the summary
  • Progress bar now tracks live up to 100%
  • Reworked nav icons
  • Overall look now leans more on the original CCleaner v4 for inspiration

Introducing FluentCleaner Classic. A 3.5 MB, CCleaner-Style Companion to the 140 MB WinUI3 App

I used to be the WinForms king... and somehow I forgot just how ugly our apps used to be. And no, the screenshot below is not a mockup. I actually downgraded FluentCleaner back to WinForms + .NET Framework.

Modern vs. Classic. Yesterday I had no idea if I should actually ship this thing... Today I did, it was public on Twitter for barely an hour before the response made it obvious there was no real decision left to make

Why this version exists

Since FluentCleaner launched, I've received a ton of feedback and a striking chunk of it was technical in nature: roughly 14% of all incoming feedback came from users who couldn't get the app to start at all, or clearly struggled with it. A big part of that comes down to footprint: the WinUI3 version ships the Windows App SDK and .NET 10 runtime, landing at roughly 140 MB unpacked across 243 files. For a lot of setups older Windows 10 builds, locked-down environments, slow or metered connections, that's a real barrier to entry

FluentCleaner Classic is the answer: a lightweight, portable EXE built on .NET Framework 4.8 (WinForms) and .NET Standard 2.0 (the shared cleaning core), running on virtually any Windows install with nothing extra to download. The result: just 20 files and 3.57 MB unpacked a fraction of the WinUI3 footprint, powered by the exact same scan engine and the same Winapp2.ini/Winapp3.ini database

Both versions are being developed in parallel and share the same cleaning core (FluentCleaner.Core), so detection/cleaning improvements land in both at once. The database (Winapp2.ini/Winapp3.ini) can be updated straight from GitHub in either app.

What's different right now

FluentCleaner Classic is a fresh, from-scratch port, it's not a 1:1 replacement yet, and I'd rather be upfront about the gaps than have you find out the hard way:

  • Not localized yet. WinUI3 ships 12 language packs (English, German, French, Indonesian, Italian, Lithuanian, Norwegian, Portuguese (BR), Russian, Ukrainian, Chinese Simplified/Traditional) via a proper per-language resource pipeline. Classic doesn't have that infrastructure in place yet, everything is currently English-only, hardcoded in the UI. Porting a full localization pipeline to WinForms takes real time to do right, and I wanted to get Classic into your hands first rather than delay it further. Language support is planned, not abandoned.
  • Compatibility is still being verified. I haven't fully audited Classic across every Windows version/edge case yet, treat it as freshly baked. If something breaks on your system, please report it.
  • Not yet at full feature parity with WinUI3. Currently missing or not yet ported to Classic:
    • Theme picker (Light/Dark/System); Classic currently uses the default WinForms look
    • In-app language switcher (tied to the localization gap above)
    • Settings export/import (backup & restore)
    • Portable-mode indicator in Settings
    • Winappx (bloatware/AppX) database support
    • Terminal page (interactive command console)
    • Rule Lab (dry-run testing window for custom cleaning rules)
    • AI-assisted custom cleaner generation (Classic's Custom page still supports manual create/edit/test, just not the AI prompt-to-rule flow)

Everything above is on the radar. Classic will keep catching up release by release.

FluentCleaner (Standard) 26.08.01:

  • [Added] Support for REG exclusions from Winapp databases and global settings
  • [Improved] Protected registry branches remain intact even when a parent key is cleaned
  • [Improved] Recursive scans now skip fully excluded directory trees instead of scanning and filtering them afterward
  • [Improved] Added a registry exclusion example to the global exclusions settings
  • [Updated] The built-in Winapp2.ini database received a massive update, growing from 3,721 to 4,075 cleaning entries
    • Added 367 new definitions and removed or replaced 13 obsolete entries
    • New and expanded coverage includes Anthropic Claude, Microsoft Copilot, Brave Origin, Adobe tools, Nexus Mods App, Outer Wilds Mod Manager, Synergy, and more
    • FluentCleaner maintains its own curated Winapp2 edition with additional app-specific entries, safer defaults, warnings, and tested rule improvements
    • Following additional compatibility testing, this curated database is now shipped as the default built-in cleaning database
  • [Improved] AI explanations now follow the selected application language
  • [Improved] Groq now uses openai/gpt-oss-120b with the current completion and reasoning parameters
  • [Improved] Cleaner analysis summary layout and placement of scan details
  • [Improved] Exclusion and post-clean controls are now disabled while their parent feature is inactive
  • [Improved] Browser cookie-cleaning entries now remain disabled by default
  • [Refactored] MainForm navigation, view initialization, localization flow, and shared UI responsibilities were reorganized into smaller, clearer components
  • [Refactored] Settings persistence was centralized while preserving compatibility with values written by the Modern edition
  • [Added] Chinese (Simplified) language support
  • [Added] Bulgarian language support
  • [Improved] German language support
  • FluentCleaner (WinUI3)
  • First version actually running on the shared FluentCleaner.Core, the same scan/clean engine Classic uses
  • Post-clean tasks now time out after 10s instead of waiting forever, a stuck shell command can no longer hang an /AUTO run