1Converting PNG to JPG on Your Mac
macOS makes image format conversion remarkably simple with several built-in tools that require no additional software. Whether you are using a MacBook Air, MacBook Pro, iMac, or Mac Studio, you can convert PNG to JPG on Mac using tools you already have. This guide walks you through every method — from the simplest Preview export to advanced Terminal commands — so you can choose the approach that best fits your workflow.
2Why Convert PNG to JPG on Mac?
Mac screenshots are saved as PNG by default (using Command + Shift + 3 or Command + Shift + 4). While PNG is excellent for preserving quality and supporting transparency, the files can be quite large — a simple screenshot might be 2-5MB. Converting these PNG screenshots to JPG can reduce the file size by 70-90%, making them much easier to share via email, Messages, Slack, or upload to websites.
3Method 1: Using the Preview App (Easiest Built-in Method)
Preview is the default image viewer on macOS and the most straightforward way to change a PNG to JPG on your Mac:
Step-by-Step Instructions
- Open your PNG file: Double-click the PNG file to open it in Preview. If it opens in a different application, right-click the file, select "Open With," and choose Preview.
- Open the Export dialog: Go to File > Export in the menu bar (or press Command + Shift + E).
- Select JPEG format: In the export dialog, click the "Format" dropdown menu and select JPEG.
- Adjust quality: Use the quality slider to set your desired level. A setting of 75-80% is recommended for a good balance between file size and visual quality. You can see the estimated file size update as you move the slider.
- Save the file: Choose a name and destination, then click Save.
This method is perfect for single-file conversions and gives you full control over output quality. The entire process takes about 10 seconds.
4Method 2: Using the Photos App
If your PNG file is already in your Photos library, you can convert it to JPG without exporting:
- Open the Photos app and locate your PNG image.
- Select the image, then go to File > Export > Export 1 Photo.
- In the export dialog, choose JPEG from the Format dropdown.
- Set the quality (Photo, Actual Size, or Small/Medium/Large) and click Export.
You can select multiple photos in the library and export them all as JPG simultaneously using File > Export > Export [X] Photos.
5Method 3: Using Automator for Batch Conversion
If you frequently need to change PNG files to JPG on your Mac, creating an Automator workflow saves enormous time. Here is how to set up a one-click batch converter:
- Open Automator from your Applications folder (or search with Spotlight).
- Create a new Quick Action (or "Service" on older macOS versions).
- Set "Workflow receives current" to image files in Finder.
- Search for and add the Change Type of Images action from the library.
- In the action settings, change the type to JPEG.
- Check "Show this action when the workflow runs" if you want to adjust settings each time.
- Save the workflow with a name like "Convert to JPG."
Now, whenever you select PNG files in Finder, right-click, go to Quick Actions > Convert to JPG, and all selected files will be converted instantly.
6Method 4: Using Terminal (For Power Users)
Advanced Mac users can use the sips (Scriptable Image Processing System) command built into macOS to convert PNG files to JPG from the command line:
sips -s format jpeg input.png --out output.jpg
To convert all PNG files in a directory to JPG, use a simple loop:
for f in *.png; do sips -s format jpeg "$f" --out "${f%.png}.jpg"; done
You can also set the quality using the sips command:
sips -s format jpeg -s formatOptions 80 input.png --out output.jpg
This approach is ideal for scripts, automated workflows, and processing large numbers of files efficiently.
7Method 5: Using Online Tools (Cross-Platform)
If you prefer not to use Mac-specific tools, our online PNG to JPG converter works perfectly on macOS. Simply open it in Safari, Chrome, or Firefox, upload your PNG file, and download the JPG. Everything runs in your browser with no server uploads required.
The online approach is particularly useful when you are working on a borrowed Mac, using a Chromebook alongside your Mac, or need to convert files on a mobile device. The consistent interface and instant results make it a reliable fallback for any situation.
8Changing Default Screenshot Format on Mac
If you find yourself constantly converting screenshots from PNG to JPG, you can change macOS to save screenshots as JPG by default using Terminal:
defaults write com.apple.screencapture type jpg
Then restart the SystemUIServer process:
killall SystemUIServer
All future screenshots will now be saved as JPG files. To revert to PNG, run the same command with "png" instead of "jpg."
9Tips for Best Results on Mac
- Use quality 80 in Preview for the best balance of file size and visual quality when converting PNG to JPG.
- If your PNG has a transparent background, choose a white background color before exporting to JPG.
- Use Automator for recurring batch tasks — it saves hours compared to converting files one at a time.
- Always keep your original PNG files as backups, especially for important screenshots and graphics.
For the fastest conversion regardless of platform, try our free online PNG to JPG converter. To learn more about format conversion, read our general PNG to JPG guide or explore how to convert any image to JPG.