How I Automated My Computer Routine With macOS Folder Actions

Feb 12, 2025 · Alexander Deplov

I’ve always believed that computers should handle repetitive tasks better than humans. It frustrates me when something can’t be automated the way I want or when simple actions require more effort than they should.

Let’s say we want to convert a video from one format to another. This often happens to me when I need to share a screencast video with colleagues on Slack. By default, macOS records in .MOV format, which is too large to share. Sometimes, I also have another file that I want to shrink for easier sharing in a message.

Previously, I used a macOS GUI app to convert in .MP4, and the steps from start to finish were:

Open the video converter app
Click a button to select a file
Select the output format
Click the “Convert” button, wait
Close the video converter app
Find and delete the original .MOV file manually

Such a simple need, yet so many manual actions were required.

So I realized that I could use the powerful macOS Folder Actions. I decided to use them as a trigger for my needs—any need. Drop the file in, and the folder action trigger does the job.

Here’s a quick demo of how much easier converting .MOV files into .MP4 has become with drag and drop. Drop a file, wait, and it’s done. It’s pure magic!

And original file deleted automatically as well.

List of My Folder Actions

After some time, I created folder actions for various tasks.

Need to convert .JPG to .WEBP? I have a folder for that.
Need to download a Twitter video? I have a folder for that.

And it’s pretty easy to set up too.

How to Set Up macOS Folder Actions

Please note that once you set up Folder Actions, you can’t change the folder name without breaking the folder actions. If you rename the folder, you must reattach the folder actions again.

Steps:

In Terminal:

brew install ffmpeg

Create and name a folder.
Open Automator and create a new Folder Action project.
Add Get Selected Finder Items and Run Shell Script. Change Pass input to “as arguments”. Select the folder.
To convert .MOV to .MP4, enter the following shell script (in all privided scripts you need to change file output path to yours):

for f in "$@"; do
    /opt/homebrew/bin/ffmpeg -n -loglevel error -i "$f" -vcodec libx264 -crf 23 -preset ultrafast -tune film "/Users/alexander/Library/Mobile\ Documents/com\~apple\~CloudDocs/Downloads/$(date +"%Y_%m_%d_%I_%M_%p_%s").mp4";
    rm -f "$f"
done

Save and exit.
Drag and drop a .MOV file into the folder. If it works, you should see gear icon in the menu bar. When it goes away - it means script is finished the task.

Additional Folder Actions

Convert Video to GIF

for f in "$@"; do
    /opt/homebrew/bin/ffmpeg -n -loglevel error -i "$f" -vf "fps=18,scale=720:-1:flags=lanczos" "/Users/alexander/Library/Mobile Documents/com~apple~CloudDocs/Downloads/$(date +"%Y_%m_%d_%I_%M_%p_%s").gif";
    rm -f "$f"
done

Convert Image to WEBP:

for f in "$@"; do
    /opt/homebrew/bin/cwebp -q 70 "$f" -o "/Users/alexander/Library/Mobile Documents/com~apple~CloudDocs/Downloads/$(date +"%Y_%m_%d_%I_%M_%p_%s").webp";
    rm -f "$f"
done

Download YouTube Videos:

In Terminal:

brew install yt-dlp

Use this script:

# Process each .webloc file
for f in "$@"; do
    echo "Processing file: $f"
    
    # Extract URL between <string> tags
    url=$(grep -o '<string>.*</string>' "$f" | sed 's/<string>\(.*\)<\/string>/\1/')
    echo "Extracted URL: $url"
    
    # Check if URL was found
    if [ -n "$url" ]; then
        echo "Attempting to download from: $url"
        
        # Download video using yt-dlp to the Downloads folder
        /opt/homebrew/bin/yt-dlp -P "~/Downloads" "$url"
        
        # Check if the download was successful
        if [ $? -eq 0 ]; then
            echo "Download successful, removing webloc file"
            rm -f "$f"
        else
            echo "Download failed"
        fi
    else
        echo "Error: No URL found in '$f'"
    fi

done

Drop a website URL directly into the folder.

Download Twitter Videos:

#!/bin/bash

# Process each .webloc file
for f in "$@"; do
    echo "Processing file: $f"
    
    # Extract URL between <string> tags
    url=$(grep -o '<string>.*</string>' "$f" | sed 's/<string>\(.*\)<\/string>/\1/')
    echo "Extracted URL: $url"
    
    # Check if URL was found
    if [ -n "$url" ]; then
        echo "Attempting to download from: $url"
        
        # Download video using yt-dlp to the Downloads folder
        /opt/homebrew/bin/yt-dlp -P "~/Downloads" "$url"
        
        # Check if the download was successful
        if [ $? -eq 0 ]; then
            echo "Download successful, removing webloc file"
            rm -f "$f"
        else
            echo "Download failed"
        fi
    else
        echo "Error: No URL found in '$f'"
    fi

done

Convert YouTube Videos to MP3 File Directly:

In Terminal:

brew install yt-dlp; brew install ffmpeg

Use this script:

# Process each .webloc file
for f in "$@"; do
    echo "Processing file: $f"
    
    # Extract URL between <string> tags
    url=$(grep -o '<string>.*</string>' "$f" | sed 's/<string>\(.*\)<\/string>/\1/')
    echo "Extracted URL: $url"
    
    # Check if URL was found
    if [ -n "$url" ]; then
        echo "Attempting to download from: $url"
        
        # Download video using yt-dlp to the Downloads folder
        /opt/homebrew/bin/yt-dlp -x --audio-format mp3 --audio-quality 0 --ffmpeg-location /opt/homebrew/bin/ffmpeg -P "~/Downloads" "$url"
        
        # Check if the download was successful
        if [ $? -eq 0 ]; then
            echo "Download successful, removing webloc file"
            rm -f "$f"
        else
            echo "Download failed"
        fi
    else
        echo "Error: No URL found in '$f'"
    fi

done

Drop a website URL directly into the folder.

Folder Actions Tweaking

If you need to change a folder action, right-click on the folder and select Folder Action Setup.

All saved actions are stored in:

Macintosh HD / Users / YourName / Library / Workflows / Applications / Folder Actions/

It’s become so powerful that I’m willing to extend this system to even more actions. Because now you can turn a folder to an interface for any conmmand line app. So now my desktop is more useful than ever: