Source: https://mactoolbox.app/how-to-batch-resize-images-on-mac

# How to batch resize images on Mac

By Nikhil Barik · Published November 3, 2026

## Quick answer

In Preview, select all the images in the sidebar and choose Tools > Adjust Size. For a set longest side, a percentage or an exact size applied to a whole folder, use Resize Images in Toolbox.

## The built-in way: Preview

1. Open all the images in one Preview window (select them in Finder and open them together).
2. Click in the sidebar and press Command-A to select every image.
3. Choose Tools > Adjust Size, enter the width and height or a percentage, and click OK.
4. Choose File > Save, or export copies if you want to keep the originals.

Preview changes the files it saves, so work on copies if you need the originals.

## The Toolbox way: Resize Images

Resize Images scales many photos at once by a percentage, to a set longest side, or to an exact width and height. You can keep proportions and choose whether smaller images should be enlarged. The resized copies go to a new folder, and the originals are left alone.

1. Open Resize Images and drop your photos.
2. Choose Resize by: Percentage, Longest Side or Size.
3. Enter the value, and set Keep proportions or Enlarge smaller images as needed.
4. Click Resize to save the copies to a dated folder in Downloads.

## Tips and troubleshooting

- To make every photo 1920 px, use Longest Side and enter 1920. Landscape and portrait photos both end up with a 1920 px long edge.
- Images already smaller than the target are left at their size unless you turn on Enlarge smaller images.
- With Keep proportions off, Size stretches images to exactly the width and height you enter.
- To also reduce file size, follow up with Compress Images.

## Frequently asked questions

**How do I resize multiple images at once on a Mac?**

Select them all in Preview and use Tools > Adjust Size, or drop them into Resize Images and click Resize.

**How do I make all photos 1920 pixels wide or tall?**

Use Longest Side and enter 1920.

**Will small images be stretched?**

Only if you turn on Enlarge smaller images.

**Can I resize to an exact size like 1080 x 1080?**

Yes. Choose Size and enter the width and height. With Keep proportions off, images are stretched to exactly that size.

## Tools mentioned

- [**Resize Images**: Scale photos by percentage, longest side or exact size.](https://mactoolbox.app/resize-images-mac)
- [**Compress Images**: Make photos smaller without visible loss in quality.](https://mactoolbox.app/compress-images-mac)
- [**Convert Images**: Save photos as JPEG, PNG, HEIC, TIFF or WebP.](https://mactoolbox.app/heic-to-jpg-mac)
- [**Rotate Images**: Rotate or flip many photos at once.](https://mactoolbox.app/rotate-images-mac)

## Keep reading

- [Resize Images](https://mactoolbox.app/resize-images-mac)
- [Images](https://mactoolbox.app/image-tools-mac)
- [All guides](https://mactoolbox.app/guides)