Batch Image Resize and Export With Preview

In Preview you can open multiple images at the same time and export them all at once in a new format. You can also resize all of the open images at once, forcing them images to scale to a specific percentage or fit into a specific size. You can also do some other things in batches, such as rotations.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: Batch Image Resize and Export With Preview.

So let's say you have a whole bunch of images like these and you want to resize and shrink them. You can see here these are pretty big. 4MG for that first one, etc. So you can use Preview to do this in batches. You don't have to do each one individually.

So I'm going to Command A to select all of them and Command O to open which will open them up in Preview. Notice I see them here on the left side as thumbnails. If you don't see you can turn on Thumbnails right here or right there. So I can see them all here and I can select one and I can do something like Export.

But if I were to select several of them, like the first two here by holding the Command key down, you can see it says Export Selected Images and I can export both of them. Or if, as I'm selecting these I hit Command A, you can see all of them are selected here on the left sidebar. Now when I say Export Selected Images it will export them all. I get to use Option to select say lower JPEG quality for them or another format.

You can also do the same thing for resizing the because these are too big. So, if I have these all selected and only if they're all selected, if I go to Tools I can go to Adjust Size. You can see the dialogue box is a little bit different than if I just had one selected. So I can set it to say, Fit into a custom size. Or I can change the percent and say do them all at 50%. So you have lots of options here.

So let's say I want them all to fit within 640 x 480. I'm going to Scale proportionally; Resample image. You can see it says Multiple Values pixels. There are 18 images here. You can see that 2MB will be the size of the new images all together. Whereas 57.1 MG was the total size for all 18 of them. So I hit OK. This will resize them all. So that's kind of nice. Now I can Export them all as well. I want to make sure I have them all selected and say Export Selected Images. I will put them on the Desktop here in a new folder called Temp. It will export them all out. If I look in Temp here I can see I've got all those new ones and they are quite small. I've been able to reduce the size of these a quite bit here over the multiple megabytes that each one was.

Now Undo works on the multiple images. So I've just converted all of these to be smaller size. But if I Undo it undoes the size change for all of them which is really nice.

Now somethings work in batches if you have all these selected. For instance, Rotate Left will rotate them all left. You can Undo. Some things will not. So if I have these all selected here and I were to go to Adjust Color and change the colors, it would only change it for this one image. You can see it changed this one but it didn't change these.

Comments: 2 Responses to “Batch Image Resize and Export With Preview”

    2 years ago

    Hi i can Command A in iPhoto but i cannot Command O them to open them in preview. Is there a quick fix for this?

    2 years ago

    Eddie: I assume you mean Photos, not iPhoto. If the images are already in Photos, you don’t need to open them in Preview to batch export them. You can do that right in Photos. Just select the ones you want, and then choose File, Export, Export Photos.

Comments Closed.