Sometimes, QuickLook doesn't work right with certain file types, even though it should. Or a file now looks different in QuickLook than it used to.
How to find out which QuickLook plugin, or .qlgenerator, is responsible for which types, and what to do about it?
Best Answer
Open Terminal, and type the following:
This will give you a fairly long list of all your active QuickLook plugins:
The types listed there might look a little strange, like
com.apple.safari.bookmark
. Those are AppleUniform Type Identifiers
or shortUTType
identifiers, and there is a list of the default ones available from Apple here. If you're looking for a specific file extension, it might be a good idea to open that link and search the page for it. A search fortxt
reveals its UTType to bepublic.plain-text
, and this is the type you will find it under in the qlmanage output.So if a particular type of file looks strange in QuickLook, just look up its path here, go there and disable it (for instance by renaming its file extension to something other than
qlgenerator
), then come back to Terminal and force QuickLook to reload its list of plugins by typingRun
qlmanage -m plugins
again to make sure the offending qlgenerator is not loaded anymore. Careful: QuickLook will even load them if they're in the trash, which is why we renamed the plugin above instead of trashing it.Open a Finder window, find a file of the right type, and hit the space bar to double-check.