Batch Resize Images on Mac with Preview
You can easily batch resize groups of images within Mac OS X by using the included Preview app, that is, taking a group of pictures set at one or various resolutions, and collectively resize them all together in a group to a new resolution, outputting either as the same file or as a new file saved at the newly desired resolution. Long ago you had to buy expensive third party software for this purpose, but no longer is there a need for any additional downloads or expensive photo editing applications to perform these tasks on a Mac. Instead you only need Preview, which is free with every Mac and every version of OS X! Here’s how to use Previews’ powerful yet easy batch image resize feature it in a few simple steps.
Batch Resize Images in Mac OS X
You will need to launch Preview, which is in the /Applications/ folder, but is also usually the default image editor and can be typically opened by just opening any picture. Once Preview is open, proceed:
- Select all the images you want resized and open them within Preview
- From Preview, select the images that you want to batch resize from the drawer (Command+A will select them all)
- Now, go to the menu labeled Tools, and then Adjust Size
- Enter a value for what you want the new width and height to be
- Next, navigate to the File menu and click “Save All” or, to save a NEW version that is resized, choose “Export Selected Images…” or “Save As”
Choose a path to save the files in the Save dialog to if you’re exporting or using “Save As” features, then just wait for all of the images to finish resizing to their new resolutions. The batch resizing takes place fairly quick, but the precise speed is dependent on your available system resources and speed of the Mac.
This works in Preview that is included in virtually all versions of Mac OS X, happy batch resizing!
Updated: 2/15/2013 for clarification, the precise language varies slightly per version of OS X but the procedure works in all Previews versions, whether it’s Snow Leopard, OS X Lion, OS X Mountain Lion or beyond.
If you are using SL you have to go to Preview/Preferences/General –> “open all files in one window”
now THIS is cool, I hate launching into bloatware Photoshop just to batch resize pictures and I had no idea Preview was so capable. If Apple adds a few more features to Preview there will be little reason to use Photoshop at all…
Be careful when you use this tip which can be useful, you’ll lose the original sized picture… There is no choice for the saving name or place.
You don’t have to overwrite the original image. If you choose ‘Export’ you can choose where to save the image. (Lion)
GRACIASSS!! Terima kasih.
[...] to resize a ton of pictures? Instead of downloading a third party application or using Preview, you can use Automator to handle the entire operation, even renaming the images to indicate they [...]
Excellent thank you!!!!!
Rick
[...] powerful app that is often underutilized for batch photo processing tasks, I use it frequently to batch resize images for wallpaper posts and other purposes, it’s quick, lightweight, and much less demanding on [...]
Very much appreciated – you’ve saved me a lot of time!
Ever since I upgraded to Lion, Preview will crash when I do batch resizes of 10 pictures or more. The more pictures I try to batch resize, the harder time it has. Both on my MBA 13 with SSD and 27″ iMac w/ SSD.
Quicklook and preview in Lion suck. Quicklook fails to launch after tens of shifts among a bunch of figures, no matter what format they are. Preview crashes if more than tens of figures are opened at the same time. Never work properly.
Simply Superb!
Thanks!!!! You saved my life!!!
Hahaha!
This is a good solution for a few dozen images but you can’t open a few hundred images and then perform the batch.
Searching for batch, I was thinking hundreds of images, this process is geared more towards a dozen or so.
If knowing this gets you closer to dropping Photoshop, you don’t know Photoshop.
[...] most Mac users will likely prefer to use Preview to batch resize images because of the ease of use, advanced users often like to go with the command line for repetitive [...]
Thank you. I also noticed that you can undo (command+z) if you want to revert back to the original file.
We’re is “SAVE ALL”?!
OS X Mountain Lion.
Thanks!
[...] Depending on the amount of images selected to convert, their resolutions – which can also be resized at the same time if desired, and their file formats, this process can either be very fast or somewhat time [...]
[...] like the iPhone screen, so you may want to save them all in a folder then take a moment to batch resize them using Preview to a resolutio that is appropriate for your needs. Ok enough chat, let’s get to [...]
Hi I am wondering if I resize will I have copies of the originals?
No – you won’t. this process replaces the existing file so make sure you have a copy if you still want to keep the original!
This just got me into big trouble.
I tried to batch process 300 photos in preview and it proceeded to open every one of them, freezing my mac.
I had to force quit. Now, however, anytime I open Preview, it commences with the process of opening all 300 pics again.
I’ve no idea what to do.
When I had a PC, I had a little program that just resized and put them all in a folder rather than opening up every picture.
Works perfectly – I reduced 137Mb of photos to just 8.8Mb in about 1 minute! Quality was still fine for use in docs.
NB: this process replaces the existing file so make sure you have a copy if you still want to keep the original!
Useless! there no SAVE ALL!! in Lion.
[...] you can also create a simple ‘Batch Resize’ Service with Automator, or just do a manual bulk resizing process on a group of pictures using Preview app, which also comes with every version of Mac OS [...]