How to Batch Convert Images Using Automator on Your Mac


Batch convert images using Automator

You can easily batch convert images from one format to another on your Mac. If you convert a lot of images often, Automator can help make that easier and faster to accomplish.

Automator is a useful utility Apple has included in their operating system since Mac OS X 10.4 (Tiger). It allows you to easily automate repetitive tasks. You create workflows using a drag and drop interface to stack actions on top of each other, like puzzle pieces, until you have included all the steps needed for your task.

Today we’re going to show you how to use Automator to create an app that will make it very quick and easy to batch convert images.

Create New Document in Automator to Batch Convert Images

Step 1: Open Automator (Automator.app) from the Applications folder. On the dialog box that displays, click New Document.

Click New Document in Automator

Step 2: In the Choose a type for your document section of the dialog box that displays, click Application. Then, click Choose.

You can also create a workflow that you can run from within Automator. However, for this task, we need to create an app that we can add to the dock.

Select Application as file type in Automator

Create the Workflow

On the main Automator window, there are two primary sections. Actions and variables are on the left and the workflow is on the right. To build an Automator action, you drag actions and variables from the left into the workflow on the right in a sequential order. You’re basically telling Automator what to do with the files we provide it step by step using the workflow.

Step 1: First, we’re going to tell Automator to create a special folder in which to put the converted image files. Select Files & Folders under Library in the first column. Then, select New Folder in the second column and drag it to the workflow on the right.

Drag New Folder into workflow

Step 2: The New Folder action is added to the workflow. You need to give the new folder a name, so type a descriptive name, such as “Convert PNG to JPG“, in the Name box. You can choose where to create this folder from the Where drop-down list. The Desktop is the default choice and we’re going to accept that choice.

Enter a name for the new folder

Step 3: The next step is to tell Automator to select the images. To do this, make sure Files & Folders is selected in the left column. Then, select Get Folder Contents in the right column and drag it to the workflow below the New Folder box.

Drag Get Folder Contents into workflow

Step 4: Now, you need to tell Automator to convert the images you give it. Select Photos in the left column. Then, select Change Type of Images in the right column and drag it to the bottom of the workflow.

Drag Change Type of Images into workflow

Step 5: A dialog box displays asking if you’d like to add a Copy Finder Items action so the copies are changed and your originals are preserved. We don’t need to do this because we’ve already told Automator to create a new folder into which copies of the original files will be placed. The original files will not be modified. So, click Don’t Add.

Click Don't Add for Copy Finder Items

Step 6: On the Change Type of Images box in the workflow, you must select to which type of images you want to convert your files. Select the type from the To Type drop-down list. We’re converting our images to JPEG, so we select that.

Select image type in To Type drop-down list

Save Your Automator Workflow to Batch Convert Images

Step 1: Now it’s time to save your Automator workflow as an app. Go to File > Save.

Go to File > Save

Step 2: On the Save As dialog box, enter a name for the Automator app file in the Save As box.

To select a different location for the Automator file, select a folder from the Where drop-down list, or click the down arrow button to the right of the Save As box to access the full Save As dialog box, which we show in the next step.

If you want to use the currently selected location in the Where box, click the Save button now. Otherwise, see the next step.

Click expansion arrow on Save As dialog box

Step 3: If you clicked the down arrow button to access the full Save As dialog box, use the panels in the middle of the dialog box to navigate to the folder in which you want to save your Automator app file. Make sure the file name is what you want in the Save As box at the top. Click Save.

Save the .app file

Close Automator

Step 1: To close Automator, go to Automator > Quit Automator.

Quit Automator

Add Automator App to Dock

Step 1: Once you finish creating your new Automator app, add it to the dock for easy access. To do this, open a Finder window and navigate to the folder in which you saved your Automator app file. Drag the .app file to the dock.

Drag the Automator app to the dock

Use Your New Automator Add to Batch Convert Images

Step 1: Now, it’s time to use your Automator app to batch convert images. Open a Finder window and select as many images as you want to convert. Drag the selected image files onto the Automator app icon you added to the dock.

Drag image files to app on dock

Step 2: Depending on the number and size of the images and the speed of your Mac, you’ll see a new folder created on your desktop with the name you specified in the New Folder box in the Automator workflow.

New folder on the desktop

Step 3: The new folder contains copies of all the images you selected, converted to JPEG (or the format you selected).

Converted image files

What kind of apps or workflows have you created with Automator? Let us know in the comments.

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