Mac comes with an in-built Screenshot app which you can open from Applications > Utilities folder. Alternatively, you can press “Command + Shift + 5” shortcut keys to open the app and capture the screen. By default, Mac will save the screenshots in desktop in PNG format. If you wonder, how to change the screenshot format to other file extensions like JPG, TIFF, PDF or GIF, here is how you can do that.
Mac Screenshot App Default Behavior
You can use “Command + Shift + 3 or 4 or 5” keys in Mac to take a screenshot using the Screenshot app. After capturing, the captured screen will be floating on the lower right corner. You can click on the screen for editing the image like crop or add text. Whether you edit or not, the screenshot will be saved in Desktop folder in PNG format.
Though PNG or Portable Network Graphics format is good for online publishing or using in your documents, they are generally larger in size. As you can see in the above screenshot image, the simple desktop capture is 7.5 MB in size with PNG format. You may need to convert to JPG format and compress for reducing the size. Alternatively, you want to save the screenshot in PDF format and share with others to avoid editing. At any case, follow the below instructions to change PNG format to different format and revert back when you need.
Taking Screenshot in Mac with JPEG Format
Follow the below instructions to use JPEG format for screenshots in Mac.
- Open Finder app and go to “Applications” folder.
- Find and open “Utilities” folder.
- Double click on “Terminal” and launch the app.
- Copy and paste the below command and press enter.
defaults write com.apple.screencapture type jpg;killall SystemUIServer
- You will not see any confirmation message but the format will be changed automatically.
- Now, capture your desktop screen with “Command + Shift + 3” keys.
- Check the screenshot image in “Desktop” folder in Finder app.
- The screenshot will be saved in JPEG format instead of PNG.
As you can see, the same desktop capture image in JPEG format is only 909KB in size compared to 7.5 MB in PNG format.
Getting Screenshot in Mac with TIFF Format
Now it’s a matter of replacing the format in Terminal command to get in TIFF output. Use the following command for capturing screenshot in TIFF format.
defaults write com.apple.screencapture type tiff;killall SystemUIServer
Use GIF Format
If you want to generate screenshot in GIF format, then use the following command in Terminal.
defaults write com.apple.screencapture type gif;killall SystemUIServer
Convert Screenshot to PDF Format
Finally, use the following command for saving screen captures in PDF format.
defaults write com.apple.screencapture type pdf;killall SystemUIServer
Remember, you can still open the PDF floating screenshot and insert annotations.
Reverting Back to PNG Format
If you want to use the default PNF format, then simply use the following Terminal command.
defaults write com.apple.screencapture type png;killall SystemUIServer
Using Convert Image with Quick Action in Finder
When you select the screenshot image in Finder app, you can see the Quick Action items below the image. You can find “Convert Image” and “Create PDF” options for all image files (not for PDF). In case if you do not see these actions, click on the “More” icon and select “Customize” option. This will open “Extensions” preferences section for Finder app where you can enable the Quick Actions to show.
Clicking on the “Convert Image” Quick Action icon will open a pop-up like below. You can select one of the formats like PNG, JPEG, GIF or HEIC to convert your image quickly. The advantage here is that you can also choose the image size as small, medium, large or actual size and see the size in KB before conversion.
Convert with Image Compression Using Preview App
As mentioned, PNG images are larger in size compared to JPEG files. This is due to the fact that PNG uses lossless compression while JPEG uses lossy compression. So, you can compress the JPEG image further to reduce the size by reducing the picture quality. Using Quick Action will not allow you to select the compression quality level for JPEG images. However, you can use Preview app to compress the JPEG image.
- Double click on your PNG screenshot image to open it with Preview app. Alternatively, hold control key and click on the file and choose “Open With > Preview” option.
- When the file is opened with Preview app, go to “File > Save As” or “File > Export” menu.
- On the pop-up, select JPEG as your format from the dropdown.
- Now, you will see an additional “Quality” slider. Move the slider to set the quality of compression level. You can see the file size will reduce/increase when you reduce/increase the quality.
- Click “Save” button to convert your image with required compression quality and size.
Full Fledged Processing of Screen Captures
Though you can edit and annotate the screenshots in Mac, you need a third-party app for creating professional documentations from the captured images. The best option is to purchase Snagit app which is a must use app for content creators and bloggers. You can link Screenshot app and Snagit to automatically open the captured screens with Snagit Editor.
After editing your screenshot, you can save it in JPEG format by adjusting the quality level of compression similar to Preview app.
PNG Vs JPG – Background Transparency
Remember, PNG format supports transparent background. This helps when you capture the selected window which always add some transparent background around the borders of the capture. If you use JPG format, the transparent portion will be converted to black background. This may not look good if you insert the images on Word or Pages documents with white background. In this case, you may need to process the image using third-party apps like Snagit to remove the white background.