It is extremely easy to make an image transparent with the help of the Preview application, the built-in image-editing application that comes with all Macs running Mac OS X. Note that creating transparent PNG or GIF images from this way works best on images. with uniform colors in the area to be transparent. The more complicated the image and color variation, the more work you’ll need to do with the alpha tool to make a part of the image transparent.
How to make an image transparent on Mac with preview
You can make any image transparent with Preview, though you’ll find that the resulting image must be saved as a transparency-compatible image format.
- Open the image in Preview
- Click the Toolbox icon on the Preview application toolbar to reveal the image editing tools
- For earlier versions of Mac OS X Preview: Click the small pen icon in the toolbar to reveal the image editing tools
Select the “Instant Alpha” tool, which looks like a magic wand in the Editing Tools menu bar (in earlier versions of Preview, it’s in the menu Selection dropdown if image is smaller than certain widths)
Click and hold the part of the image you want to make transparent, and while holding still move the cursor up or down to select more or less of the image to make transparent; anything red will become transparent
Press the Delete key or go to the Edit menu and select “Cut” to remove everything that was highlighted in red with the Alpha tool (note: if the original image was in a format that does not support transparency, you will be will ask you to convert the document, choose “Convert” to continue” as expected Repeat as needed for other parts of the image you want to make transparent
To make the finer details transparent, it can help to zoom in and out with Command+Plus and Command+Minus keys.
If the original file was a PNG or GIF and you’re satisfied, you can save as usual, but in many cases you may not want to overwrite the original file. Instead, you can save the newly transparent image as a copy using “Export” or “Save As”.
Exporting the image as a PNG or transparent GIF
PNG files are much higher quality than GIF, and for most uses you’ll want to use a transparent PNG, but we’ll cover creating and saving as a transparent GIF or PNG anyway.
Save a transparent PNG
- Go to File and choose “Export”
- Select “PNG” from the dropdown menu and check the box next to “Alpha” to ensure the image maintains its transparency
- Save as usual, keep the .png file extension
Save as transparent GIF
- Go to File and select “Export”, then Option-click the file formats menu to reveal “GIF” as an option
- Check the “Alpha” box to preserve the transparency of the image, then save as usual with a .gif extension
Since you’ll need to do manual adjustments with the alpha tool, this wouldn’t work on a group of files, although you could batch convert them ahead of time . to PNG or GIF, then open each one individually to make them transparent.
The following video shows the process of turning an image into a transparent version of itself, including cleaning up areas that weren’t immediately captured by the alpha tool using the zoom. This is demonstrated in an earlier version of Preview where the Edit Tools button was the Pencil instead of the modern Toolbox icon; otherwise, everything else is the same:
You can create transparent images in Preview for Mac with almost any version of the app this way, whether you’re on a modern version of macOS or a version of Mac OS X, the preview application can easily create transparent gifs and transparent PNG files. Just remember to look for the toolbox button in modern preview builds and the pencil button in older preview builds.
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