A new portable, open-source cleanup utility for Windows can erase over 30 gigabytes of disposable files on a typical PC, according to its developer. FluentCleaner, released by well-known Windows customization developer Builtbybel in April 2026, combines a modern WinUI 3 interface with community-powered cleaning rules to offer a free alternative to CCleaner that never requires installation or collects user data.

A closer look at FluentCleaner

FluentCleaner arrives as a single executable file under 5 MB. There is no installer, no background service, and no nag screen. Builtbybel, the developer behind popular tweaking tools like ThisIsWin11 and Bloatynosy, built it on .NET and the WinUI 3 framework, giving it the design language of Windows 11 without the overhead of a packaged app.

The tool’s cleaning engine is fueled by the winapp2.ini file—a community-curated database of over 2,000 cleaning routines that has been maintained by CCleaner power users for nearly two decades. Unlike CCleaner, which ships its own proprietary cleaning definitions, FluentCleaner puts the open list front and center, and lets you pick exactly which items to scan.

Three capabilities separate FluentCleaner from other disk cleaners:

  • Item-level preview: Before deleting anything, you can expand any detected category and see every file that would be removed. The preview respects your folder view preferences—thumbnails for images, details for documents—so you know precisely what you’re giving up.
  • Selective recovery: FluentCleaner marks many entries as “recoverable” by moving them to the Recycle Bin rather than performing a permanent delete. If you change your mind, you can restore files the same way you would any other deleted item.
  • Custom rule editor: A built-in editor lets you author, test, and share your own winapp2.ini entries. Power users can push new definitions to the community, making the tool smarter over time.

The 30 GB claim comes from a full scan of a year-old Windows 11 installation with common developer tools, browsers, and media editors. Your mileage will vary, but early adopters report reclaiming 15–40 GB after their first pass.

What FluentCleaner means for you

For everyday Windows users

If the term “winapp2.ini” makes your eyes glaze over, don’t worry. Out of the box, FluentCleaner presents a categorized checklist with safe-to-clean items already ticked. The interface borrows familiar patterns from Windows Settings: collapsible sections, search-as-you-type filtering, and clear visual indicators for recoverable items. You can free several gigabytes in under two minutes without reading a manual.

The portable design is especially handy for family tech support. Put the exe on a USB stick, plug it into a relative’s sluggish laptop, and run a cleanup without leaving any software behind.

For power users and system administrators

FluentCleaner finally gives you a transparent, scriptable cleaning engine that respects the winapp2.ini standard. You can swap in your own ini file—perhaps one with aggressive developer-focused rules that clear NuGet caches, Python pip temp files, or Docker build layers—and run it silently from the command line. Because it’s open source (MIT license), internal IT teams can audit the code, lock down which rules are allowed, and deploy it via any software distribution tool without worrying about licensing.

For environments where CCleaner’s forced registration and telemetry are non-starters, FluentCleaner is a drop-in replacement. It performs deep scans for browser leftovers, Windows Update caches, thumbnail databases, and dozens of other space-hungry locations without phoning home.

For the privacy-conscious

CCleaner’s reputation suffered after Avast bundled adware into the installer, then suffered again when the 2017 supply-chain attack injected malware into the official 32-bit build. Many users have been searching for a trustworthy alternative ever since. FluentCleaner’s portable, open-source nature means you never run an installer that could be tampered with, and the community can inspect every line of code.

The long road away from CCleaner

CCleaner dominated the Windows cleanup space for over 15 years. At its peak, it was the go-to utility for clearing temp files, browsing history, and registry entries. But starting around 2017, a series of missteps eroded user trust:

  • August 2017: Piriform (acquired by Avast) disclosed that a compromised version of CCleaner 5.33 had been distributed for nearly a month, infecting 2.27 million users with a backdoor.
  • 2018–2020: Free versions began pushing Avast antivirus during installation, with confusing opt-out designs. Forced updates from version 5.45 onward removed user choice and introduced data collection.
  • 2021–2024: The product’s registry cleaner, long criticized for causing more harm than good, became harder to skip. The UI grew cluttered with upsells for driver updaters and performance optimizers.

Alternatives emerged: BleachBit offered open-source cleaning but lacked the polish and up-to-date rules of CCleaner. Privacy Eraser focused on secure deletion but carried a high price tag. Winapp2.ini remained a powerful but nerdy option that required manual setup with CCleaner itself—a circular dependency.

Builtbybel saw the gap. After creating tools that helped users debloat Windows 11 and customize its shell, a dedicated cleaner was the logical next step. FluentCleaner launched as a public beta in late 2025 and reached its first stable release on April 14, 2026.

How to start using FluentCleaner today

Step 1: Get the tool
Visit Builtbybel’s GitHub repository and download the latest FluentCleaner.exe from the Releases section. No installer required.

Step 2: Run an initial scan
Launch the executable. Windows SmartScreen may show a warning—this is normal for any new, unsigned application. Click “More info” and “Run anyway” after verifying the file’s SHA-256 hash against the one published on GitHub.

Step 3: Review what’s selected
The default profile marks items that are considered safe to delete on most systems: browser caches, temporary files, delivery optimization files, and log folders. Expand any category to see individual files.

Step 4: Customize if needed
Toggle additional items if you understand the consequences. For example, “Thumbnail Cache” can grow to several gigabytes and is safe to remove, while “Windows Error Reporting Files” may be useful for troubleshooting crashes.

Step 5: Clean
Click the Clean button. Recoverable files move to the Recycle Bin; others are permanently deleted. If you accidentally remove something you need, check the bin immediately.

Step 6: (Optional) Set up automatic cleaning
Power users can schedule FluentCleaner with Task Scheduler using command-line flags. The --silent mode skips the UI and outputs a log, making it perfect for weekly maintenance scripts.

A word of caution: FluentCleaner does not include a registry cleaner, and that’s by design. The developer considers registry cleaning unreliable and potentially dangerous. If you’ve been conditioned to “clean” your registry, this tool won’t do it—and that’s likely a good thing.

What to watch next

Builtbybel has teased a Microsoft Store version that runs in a sandboxed container, though that edition would lose some deep-cleaning capabilities due to Store restrictions. A planned community plugin system could let users contribute custom cleaning modules without touching the core code. Meanwhile, the winapp2.ini community is already adding rules for emerging apps like Arc Browser, Dev Home, and the new Outlook client, so FluentCleaner will stay relevant as Windows evolves.

For a utility that costs nothing, leaves no trace, and puts you in full control, FluentCleaner is the most compelling CCleaner alternative to arrive in years. Whether you need to reclaim 30 GB or just keep your SSD tidy, it’s worth a download.