How does Klyr Disk calculate folder size?
Klyr Disk enumerates readable regular files and adds the allocated size that macOS reports for each file. Apple defines total file allocated size as the allocated size in bytes, including file metadata. Klyr Disk uses those file values to build a navigable folder hierarchy.
A folder total is therefore a subtotal of the readable filesystem tree—not a replacement for APFS container accounting. Snapshots, purgeable space, shared blocks, clones, cloud placeholders, mounted volumes, and protected locations can make Finder, System Settings, and a directory scan show different totals.
How are exact duplicates verified?
Klyr Disk uses a two-pass method. It first groups regular files with the same byte size; differently sized files cannot be exact copies. It then calculates SHA-256 hashes only for candidates in matching-size groups. Files must have the same size and content hash to be reported as exact duplicates.
A verified match is not an instruction to delete. Identical files can still be required at two different paths, belong to a backup, or share physical APFS blocks. See the 100-file duplicate verification test and the detailed duplicate finder guide.
Can Klyr Disk access every file on a Mac?
No. Apple requires user consent for protected file access and lets the user control Full Disk Access in Privacy & Security settings. Apple’s macOS file-access security guide describes this consent model.
Klyr Disk Lite is sandboxed and analyzes folders the user explicitly selects. Klyr Disk Pro can inspect more privacy-protected locations after the user grants Full Disk Access, but that permission does not override every protection, unlock encrypted data, or make cloud-only content local. Klyr records denied reads and marks the scan partial or access-limited. See the access-limited scan case study.
What happens before a file moves to Trash?
Klyr Disk does not delete files automatically. It presents paths, sizes, categories, and reasons for review. When the user acts, Klyr validates the selected path again, applies protected-path and sensitive-location checks, then uses the normal macOS Trash workflow.
Trash is a recovery boundary, not a backup. Users should confirm important data is backed up and verify affected apps or projects before emptying Trash.
What leaves the Mac?
Core storage enumeration, folder-size calculation, duplicate hashing, and file classification run locally. Klyr Disk does not need to upload a file inventory to perform those scans. Internet access is used for product delivery, purchase verification, activation, updates, Sign in with Apple, and optional third-party AI features.
Optional AI features require the user’s own provider key and are separate from local scanning. Read the complete privacy policy for data handling and service-provider details.
What does the Disk Health score mean?
Disk Health is a storage-management score based on free-space headroom and recorded storage trends. It helps explain capacity pressure and whether used storage is growing or stable. It is not a SMART status, SSD wear measurement, hardware diagnosis, malware scan, battery score, or overall Mac performance rating.
Evidence and product boundaries
Review the public engineering case studies for fixtures, expectations, observed results, and limitations. Product behavior can change; the version and update date on each page show which claims were reviewed.