QuickLookDoctor
QuickLookDoctor is a free macOS utility that helps fix Finder Quick Look preview conflicts by showing which extension handles a file.
What is QuickLookDoctor?
QuickLookDoctor is a macOS utility for diagnosing and fixing Quick Look preview conflicts in Finder. It helps users understand why pressing the Space bar shows the wrong preview for a file and lets them choose which Quick Look extension should handle that file type. The app is aimed at Mac users who work with Markdown and other document formats that may be claimed by multiple preview extensions. You can drop a file onto the app, review which extensions claim its type, see which one is actively serving the preview when available, and apply a preferred handler. QuickLookDoctor also includes confirmation details about what else may be affected when an extension is ignored, plus Undo support for reversing a change. Published by Brett Terpstra, it is offered as a standalone utility for macOS.
Key features
- Diagnose which Quick Look extensions claim a dropped file type
- Show which extension is currently serving the Finder preview when available
- Choose a preferred Quick Look handler for a file type
- Ignore competing preview extensions with confirmation before changes are applied
- Undo a repair change if you need to revert it
- Copy a plain-text diagnostic report for troubleshooting or support
Review app leftovers with diCleaner
Inspect caches, support files, containers, and login items before cleaning.
Safety overview
Status: Safe
QuickLookDoctor is a legitimate utility for managing Finder Quick Look behavior on macOS. Its changes are focused on preview-extension handling, which is normal for its purpose, but changing handlers can affect how multiple file types preview in Finder if one extension supports more than one format. Use it when you want to correct incorrect Space bar previews, and read the change confirmation before applying a repair so you understand what other previews may change.
Recommendation: Keep QuickLookDoctor if you use Finder Quick Look and want an easier way to resolve preview conflicts without Terminal commands. If you do not troubleshoot Quick Look issues or no longer need it, you can remove it with little impact beyond losing this repair tool.
Common paths
/Applications/QuickLookDoctor.app
Share your experience
Be the first to share your experience.