How to

Use Folder Actions

Access the feature

In macOS High Sierra or later, Ctrl–click the folder to act on. Choose Services > Folder Actions Setup. (The location in the menu varies on older versions of macOS, but the first step is always to Ctrl–click the folder.)

Set up an alert

When the Folder Actions window opens, select ‘add — new item alert’ and click Attach. When the window closes, make sure Enable Folder Actions is check marked, as well as the folder and script you just set up.

Convert image formats

Screenshots in macOS will save as PNG files by default. An easy way to convert them to JPEGs (to email, say) is to create a folder, Ctrl–click it and add the ‘Image — duplicate as JPEG’ folder action. Drop PNGs in it to convert.

Actions in Automator

Go to the Applications folder and open Automator. In the opening window, choose Folder Action and press Choose. Click the Choose Folder pop–up menu and navigate to the folder on which you want to run the action.

Make a renaming action

We want to do three things with this action: duplicate the file, rename the duplicate, and move it to a subfolder (leaving the original intact). Start by creating a subfolder and giving it an appropriate name — like ‘renamed files’.

Add a duplicated action

In Automator’s left–hand sidebar, select Files & Folders. Then in the list to the right of that, drag Copy Finder items into the main pane. Click the To pop–up menu, then browse to and choose the subfolder you created.

Add a renaming action

Locate Rename Finder Items in the list and drag it underneath the Copy Finder Items action. Choose your criteria for renaming files from the top menu, then type text or choose the parameters from the options that appear.

Save and test

Choose File > Save and give your action a name. Quit Automator, then test the action by dragging a file from anywhere in Finder into the folder created earlier. You should see it copied and renamed within a few seconds.