How to Use macOS Automator to Batch Resize and Rename Images

The Frustration of Manual Image Editing

If you have ever transferred a batch of photos from your smartphone to your Mac with the intention of uploading them to a website, you know the struggle. Modern smartphone cameras capture massive files, often exceeding 5MB each. Uploading 50 of these to a WordPress blog or an online gallery will cripple the website’s loading speed.

Most users solve this by opening a photo editor (like Preview or Photoshop), opening each image individually, clicking “Resize,” typing in the new dimensions, saving the file, and then manually renaming it from IMG_9483.JPG to something descriptive like vacation-2023-01.jpg. Repeating this process 50 times is mind-numbing.

You do not need to buy a third-party batch-processing app to solve this. Your Mac includes a built-in, incredibly powerful tool designed specifically for this exact scenario: Automator.

In this guide, we will build a custom Automator “Quick Action” that allows you to highlight dozens of images, right-click them, and instantly resize and rename them all with a single click.

Launching Automator and Creating the Workflow

Automator is a visual scripting tool that allows you to drag and drop pre-built actions to create automated workflows.

1. Press Command + Space to open Spotlight, type Automator, and press Return.
2. A window will appear asking you to choose a document type. Select Quick Action (on older versions of macOS, this might be called a “Service”) and click Choose.
3. Look at the top of the workflow area on the right. Set the dropdown menu next to “Workflow receives current” to image files in Finder.

You have now created the foundation: a script that activates when you right-click image files in the Finder.

Building the Script Steps

The left side of the Automator window contains the Library of actions. We need to drag three specific actions into the workflow area on the right, in this exact order.

Step 1: Copy the Original Items (Crucial Safety Step)

If we tell Automator to resize the images, it will overwrite the original high-resolution files. We want to preserve the originals and create resized copies.

1. In the Library search bar (top left), type Copy Finder Items.
2. Drag the “Copy Finder Items” action into the workflow area on the right.
3. By default, it is set to copy them to the Desktop. You can change this to a specific “Resized Images” folder if you prefer.

Step 2: Rename the Copies

Now we want to rename these new copies sequentially.

1. In the search bar, type Rename Finder Items.
2. Drag it into the workflow area, dropping it exactly below the first action.
3. Automator might warn you that renaming will change the files and ask if you want to add a Copy action. Since we already added one in Step 1, click Don’t Add.
4. In the Rename action block, click the dropdown that says “Add Date or Time” and change it to Make Sequential.
5. Select new name, and type a base name (e.g., website-image). Ensure “Make all numbers” is set to 2 or 3 digits (e.g., 01, 02).

Step 3: Scale (Resize) the Images

Finally, we reduce the file size.

1. In the search bar, type Scale Images.
2. Drag it into the workflow area, below the Rename action.
3. Click Don’t Add if prompted with the safety warning again.
4. In the Scale Images block, type the maximum pixel width you want the images to be (e.g., 1200). Automator will proportionally scale down any image larger than 1200 pixels wide while maintaining the correct aspect ratio.

Saving and Using Your Quick Action

Your workflow is complete. It copies the files, renames them sequentially, and scales them down.

1. Go to the top menu bar, click File, and select Save.
2. Name your Quick Action something highly descriptive, like “Resize and Rename for Web”.
3. Close Automator.

Now for the magic. Open a Finder window and locate a folder full of large photos.

1. Highlight 10 or 20 photos.
2. Right-click the highlighted group.
3. Scroll down to the bottom of the right-click menu and hover over Quick Actions.
4. Click your newly created Resize and Rename for Web option.

Within seconds, a brand new set of properly named, web-optimised images will appear on your Desktop, ready for upload.

Conclusion

Automator is one of macOS’s best-kept secrets. By investing five minutes to build a simple drag-and-drop Quick Action, you can permanently eliminate the tedious, repetitive work of manual image formatting from your daily workflow.