Home » macOS » Use Mac’s Preview App like a Pro with These Tips & Tricks 

Use Mac’s Preview App like a Pro with These Tips & Tricks 

by Mrinal Saha

Mac’s Preview app is like a swiss army knife. On the surface, it may look like a regular image viewer. But, only when you dig in little deeper, you’ll see how useful it can get.

Every once in a while, I discover something new in the preview. For instance — you can encrypt a PDF file, make batch changes to images, or you can even use it as a mini photoshop. So let’s see some tips and tricks to get more out of Mac’s preview app.

Preview Tips & Tricks

#1 Password protect a PDF with Preview 

Say you want to send a confidential document to your colleague. Now, if this was on Windows, then you might have to purchase expensive software like Adobe Acrobat; but thankfully on Mac, you can password protect a PDF with the built-in preview app.

Simply open the PDF file with Mac’s preview. Next, go to File > Export as PDF. A new window will open, click on Show Details. Now check mark Encrypt option > assign password > save changes. And well that’s it.


#2 Batch resize photos with preview

In other OS, you have to download a third-party software to resize bulk photos. But fortunately, this feature is inbuilt the preview app.

Select all the images you want to resize and open them inside preview. Next, again select all those photos from the left side thumbnail drawer, then go to Tools > Adjust Size > Enter the new height and width. Then go to File > Save all. If you want to save a new copy of resized images then choose the Export option under the file menu.



#3 Batch change file extension with preview

I use this feature all the time when I take screenshots on my Mac. So, by default Mac uses .png format for screenshots since it’s good for text and transparency. But, jpg is better suited for the web, due to its small size. Now, instead of individually changing each image’s extension, why not automate this with preview.

To do this, select all the images and open them with preview. Now click on the thumbnail of one image and do CMD +A, to select all image. Next, go to file > exported selected image > change format to whatever you like.


#4  Create a new file from the clipboard

Say you find an image on the web, that you’ll like to save on your computer, then you don’t necessary have to download it. Like photoshop, Preview can also paste images from clipboard. Simply copy the image to your clipboard. Open preview > File > Copy from clipboard.


#5 Edit Images and PDF with preview 

Believe or not, but the preview app is also a decent image/PDF editor. You can add text, put arrows and boxes around in the image or PDF, or even play with the color and saturation of an image.


Overall, it’s not as versatile as photoshop (obviously) but sometimes, I do use it for light image editing and the results are quite satisfactory.

#6 Split or Combine pages with preview 

Say you have a multi-page PDF file and you want to add or remove few pages from between. Well, it’s quite simple to do this on the preview app. All you have to do is simply drag and drop PDF from the preview’s thumbnail drawer and it’ll magically become the part of the document.


#7 Remove background from the images

Preview has a quick selection (instant alpha and smart lasso) tool like photoshop, this lets you extract the part of the image. And if the part is of the same color (like a profile picture with uniform background) then you can easily remove the background.


To start with, open the image in the preview. Next, click on the briefcase icon to bring up the markup tool. Click on the instant alpha icon, now holding down the left click, drag it on the part of the image with the uniform background. Once satisfy, press the delete button to remove the selected part.


#8 Digital signature

Sometimes you have to send a self-attested copy of the document for legal issues. Now the traditional way to do it is — first print the document, sign it physically and then rescan it. Right?

But thankfully, preview has this life-saving feature called digital signature. With this, you can simply sign the document on your screen with the trackpad, or you can sign with a black pen on white paper and then hold that signature in front of a webcam. It’ll automatically import that signature to the PDF file. Saves time.


Closing words

Preview is good for handling batch images and small image editing work. Although it can not replace photoshop, but for light work, you should consider it before you buy expensive software.

You may also like