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Quickly previewing CDL files in macOS Finder with this QuickLook plugin

I have often needed a quick way to review the contents of a .cdl file.

CDL files contain ASC-SOP and SAT values which are used to transfer colour grading information between programs.

In simpler words, they are a set of creative instructions to push red, green or blue values of an image in a particular way.

Sure, it can be quickly opened and understood using a text editor since the structure of an ASC-CDL file is XML.

But if you have 20 to 30 .cdl files, each for one clip on a camera roll, you need a quicker way to view those values.

An example of the QuickLook preview window on an example .cdl file in Finder in macOS Mojave 10.14.6 with Dark Mode.

It is obviously not a great visual way of understanding the colour instructions, as you can only see the numbers themselves:

<Slope>1.13947 1.13502 1.13947</Slope>, and so on.

But this is enough for me to quickly determine if two or more grades are the same, since I can see if the numeric values inside are identical.

A plugin for Finder on macOS

The above is achieved using a plugin for Finder’s QuickLook function, installed into the user’s Library folder.

Fabio Lecca (@fabiolecca) wrote this QuickLook plugin to display XML files: colorxml-quicklook on GitHub.

I have simply modified it to support .cdl files.

This is done by adding an extra entry to LSItemContentTypes inside Info.plist, which is the dyn signature of the file:

# Line 16
+        <string>dyn.ah62d4rv4ge80g3dq</string>

Lecca has welcomed additions of other XML filetypes to the program, but I can’t find a working email address for him.

And I otherwise needed the functionality immediately, so I made the change myself first.

I also include it for for download below, with links and credit back to Lecca’s repo.


Download link: colorxml.qlgenerator_(seb_cdl).zip (GitHub Gist)

Originally forked from colorxml-quicklook on GitHub, authored by Fabio Lecca.


  1. Unzip colorxml.qlgenerator_(seb_cdl).zip
  2. In Finder, Go -> Go To Folder (Shift+Cmd+G): ~/Library/QuickLook
  3. Paste the colorxml.qlgenerator file inside.
  4. Relaunch Finder


Tested on macOS Mojave 10.14.6. No other OS variants tested to date.

Article first published on 24 May 2021.