Cirrus is a free Mac utility from The Eclectic Light Company that gives you a deep, itemised view inside your iCloud Drive folders — surfacing sync state, file metadata, and cloud-storage details that Finder deliberately hides.
What is Cirrus?
Cirrus is a dedicated iCloud Drive inspector for macOS. While Finder shows you a reassuring tick mark (or a perpetually spinning cloud icon), Cirrus goes beneath that surface and reports exactly what iCloud actually knows about every file and folder: its local sync status, whether it has been evicted to the cloud, its modification date as understood by the server, and any error states that might explain why a file refuses to sync.
It ships from The Eclectic Light Company — Howard Oakley's one-person Mac utility house, which has quietly produced some of the most technically rigorous diagnostic tools available for macOS. Cirrus fits squarely in that tradition.
What does Cirrus do best?
Cirrus excels at making iCloud Drive's hidden internals legible. The moment you point it at a folder, it walks the entire tree and classifies every item: downloaded and current, downloaded but stale, pinned locally, or uploaded to iCloud and evicted from local storage. That last category — files Apple has quietly removed from your SSD to save space — is where Cirrus earns its keep.
Beyond sync status, Cirrus reports the extended attributes that iCloud plants on files: com.apple.icloud.itemName, container identifiers, and the package-level flags that distinguish a true local copy from a stub placeholder. If you have ever stared at a spinning cloud badge wondering whether a file is actually safe, Cirrus turns that anxiety into a concrete answer.
I find it invaluable before going offline. A two-minute Cirrus scan of my working folder tells me with certainty which documents are physically on my SSD and which ones would silently fail to open on a plane. No other tool I have tried — not iStatistica, not DaisyDisk, not Terminal's brctl — surfaces this combination of data in a single readable window.
Is Cirrus free?
Yes — Cirrus is free to download directly from The Eclectic Light Company's website. There is no trial period, no in-app purchase, and no subscription. Howard Oakley releases his diagnostic utilities as a public service to the Mac community, supported by reader donations and his prolific technical writing. You can use every feature from the first launch without paying a penny, though a donation is well-deserved.
Who should use Cirrus?
Cirrus is built for power users who depend on iCloud Drive for real work — photographers managing large Lightroom libraries in iCloud, writers who keep manuscripts synced across multiple Macs, developers versioning project files through iCloud instead of Dropbox, and anyone who has ever lost time to a mysterious sync failure with no explanation.
It is equally useful for IT professionals supporting small teams on iCloud Drive. Diagnosing why a shared folder is not propagating correctly used to mean hunting through Console logs or running cryptic brctl commands in Terminal. Cirrus compresses that investigation into a visual scan anyone can interpret.
Novices who just want to free up space may be better served by macOS's own Optimise Storage panel, or by CleanMyMac. Cirrus rewards the curious and the systematic — those who want to understand what iCloud is doing, not just nudge a slider.
How does Cirrus compare to using Terminal?
The brctl command-line tool can query iCloud state, but it returns raw output that requires cross-referencing Apple's sparse documentation. Cirrus translates those same underlying APIs into a browsable folder tree with human-readable status labels. Where Terminal gives you hex flags and opaque UUIDs, Cirrus gives you a sortable table you can scan in seconds. For anyone not comfortable writing shell scripts around brctl diagnose, Cirrus is categorically faster to use in practice.
What are the best Cirrus alternatives?
There is no direct competitor that does exactly what Cirrus does. iCloud Drive's own Finder integration is the closest native option, but it hides most of the state Cirrus exposes. Transmit 5 by Panic can connect to iCloud Drive as a remote filesystem and shows some metadata, but its focus is file transfer rather than sync diagnostics. For general disk inspection, DaisyDisk and OmniDiskSweeper show size breakdowns but ignore sync state entirely. If your goal is specifically understanding what iCloud is doing to your files, Cirrus has the field essentially to itself.
