Change the format from screenshot picture from Grab on Mac

In my previous post, I have introduced some other good software to capture your Mac OS’ screen; in that post, I mentioned a little about the shortcut keys to take screenshot instead of launching Grab. Some people might notice that, when you use Grab to take the screenshot, you can’t really set the image format from PNG to anything else without any other software. Sometimes we wish we can just hope that we can screenshot our screen and get a PDF file right away; well, let’s turn to our almighty Terminal again.

Before we apply the command line on Terminal, we first take a screen of my blog and see what we will get:

By default, Mac OS’ screenshot format is .PNG; they hide the extension for you but once you open it with other programs or if you check the image detail information, you will see there is an extension after the file’s name.

If you want to take a close look at this picture, you can view it here: Screenshot in PNG file.

Now, let’s launch Terminal (“Applications/Utilities/Terminal”), and type in the following command line (You can just copy and past into it):

defaults write com.apple.screencapture type PDF

Then hit enter, and followed by log out your account or restart your Mac.

When we try to do the same screenshot again, we obviously can see something different:

See the file type on the preview icon? It says PDF. That’s exactly what I wanted.

You can take a look at the PDF file here: Screenshot in PDF file.

By comparing these two files, I found that the PDF file is slightly smaller size than the PNG file, 360KB vs 436KB. Why? I don’t know. Is that useful in this era? It depends.

So far I know that Grab supports the following formats:

• png (default)
• pdf
• jpg
• jp2 (JPG2000)
• gif
• tif (TIFF)
• bmp
• pict
• tga

That means you can change the PDF to TIFF in the command line; if you don’t like it, just change it back to TIFF. Just make sure you need to log out and log back in or restart before the command takes effect.

Someone might want to ask, can I change it to JPG or GIF? I haven’t really tried it, why don’t you try it yourself and tell me the result? Learning is about exploring, isn’t it? Have fun, .