Is there a command line utility to which I can pass a filename, that will return applicable UTIs for that file?

For example:

hypothetical-uti-fetcher /Library/Desktop\ Pictures/Aqua\ Blue.jpg

might give me:


4 Answers 4


You can use the mdls command to find the UTI for a file:

mdls /Library/Desktop\ Pictures/Aqua\ Blue.jpg

and it will give you a bunch of info, toward the top it will say something like

kMDItemContentType             = "public.plain-text"

Hope this helps!

  • 4
    Excellent. Thanks. mdls -name kMDItemContentTypeTree /Library/Desktop\ Pictures/Aqua\ Blue.jpg is exactly what I wanted.
    – smokris
    Nov 10, 2010 at 0:41
  • You're welcome, I'm glad this helped.
    – Wuffers
    Nov 10, 2010 at 1:06
  • 2
    Suppose I turned off my Spotlight index and I seem to have no metadata stored. (mdls whatever-file just says that the file was not found). How do the md* services generate the content types in the first place? Feb 17, 2015 at 17:53
  • Even more concise, would be mdls -name kMDItemContentType <filename> | awk -F\" '{ print $2 }'
    – luckman212
    Aug 20, 2020 at 16:18
  • Even more concise, would be mdls -name kMDItemContentType <filename> Apr 5, 2021 at 13:15

The mdls command only seems to work on Spotlight indexed files. If you run it on a mounted disk image, cd or thumb drive it may return no information at all.

When you're developing a Quicklook Plugin it's also useful to use the following command to see what UTIs Quicklook thinks a file has and which plugins it uses for the preview:

qlmanage -d 4 -p /path/to/file
  • The cited site is no longer available.
    – Randall
    Jan 15, 2019 at 10:36

Even if Spotlight hasn't indexed the file you can still use mdls to find the UTI using:

mdls -name kMDItemContentType /path/to/file


You get create a workflow for getting the UTI from selected file.

on run {input, parameters}
    tell application "System Events"
        set ff to item 1 of input
        set uti to type identifier of ff
        set ans to display dialog uti buttons {"Copy to Clipboard", "OK"} default button "Copy to Clipboard"
        if button returned of ans is "Copy to Clipboard" then
            set the clipboard to uti
        end if
    end tell
end run

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