Preview App Magnifier

If you have used the Mac OS for any length of time, you have used the Preview App. It is kind of a “Swiss Army Knife” type app that can do a lot of different things. Specialized apps can do each of Previews functions better, but for a ‘down and dirty’ fix it works fine. One of Previews little known functions is the Magnifier Tool.

Preview Magnifier

So, you are probably wondering how you would use the Preview app Magnifier Tool. Well, you could use it to enlarge a certain item in a photo (it does not really enlarge it, it just kind of expands the pixel information that is available). Perhaps you might use it to “read the fine print” on a document. I am sure there are other uses.

Let’s take a photo for example. This is a photo of the inside of my Late 2012 iMac opened in the Preview app. I took it during my recent upgrade to a Crucial MX300 SSD:

Pay particular attention to the Western Digital hard drive. Let’s say we wanted to read some of the information off the drive. Just go to the “Tools” menu and choose “Show Magnifier”:

When you do that your cursor becomes the “Magnifier Tool”. Now, just move it over the portion of the photo (or document) that you wish to magnify:

Now you can read the information off the drive, the serial number or whatever information you need.


This is no big deal, but it may come in handy if you need to magnify a portion of a photo or document to get a more refined view of that item.