QLProviderInspector
A focused tool to understand how macOS classifies files (UTIs), which Quick Look providers match them, and which apps are registered as default viewer/editor. Part of the Obscure Essentials collection.
What it does
- Inspect a file or folder via File → Open…, Open Recent, or drag & drop.
- Identify the item’s UTI (Uniform Type Identifier) and its conformance tree.
- Show which Quick Look providers claim support for those UTIs.
- Show the default viewer and editor apps for the UTI (LaunchServices).
Tip: Use “Copy Report” to copy the full report text.
Designed for clarity
Quick Look matching can be surprising — UTIs can have multiple inheritance and multiple providers can match equally well. QLProviderInspector highlights ambiguous matches and shows both tree and graph views.
No accounts, no telemetry, no network calls.
Permissions
The app inspects only the items you choose. If distributed as a sandboxed build (e.g., Mac App Store), access to /Applications can be granted optionally to improve provider discovery.
- Optional Applications-folder access is stored as a security-scoped bookmark on your device.
- Without it, the app still works but may miss providers shipped inside third-party apps.
Get help
The full help documentation is available here: QLProviderInspector Help.
For feedback and bug reports, email support@losko.de.