How to compress JPG on Mac: Easy methods for any user

As our phone cameras are becoming more capable of producing high-quality photos, the file size of those photos increases as well. Compressing the images comes in handy as it saves storage space, improves website performance, and makes it possible to share the images faster.

Mac makes it easy to compress jpg files as there’s a built-in tool within Preview. For more control and bulk compressing, you can also opt for more advanced tools like Squash, PhotoBulk, and Permute. In this guide, I’ll show you the details of how to compress JPG files to reduce their size.

Want to…	What to do
Reduce JPEG file size without losing quality	Use Preview’s Export feature to adjust format and compression settings.
Shrink JPEG without losing quality	Use Preview to export as TIFF and choose JPEG in the Compression drop-down.
Retain file quality	Use Permute to convert to less heavy but high-quality formats
Compress multiple images	Compress your file folder with the right-click menu. Alternatively, use PhotoBulk or Squash to reduce file size in bulk.
Compres files online	Use web compressing tools like ShortPixel, JPEG Optimizer, or TinyPNG.

For anything that goes beyond a simple settings tweak, it's worth running your symptoms through the Fix My Mac fix Mac issues assistant. It helps narrow down the cause before you start changing things you don't need to change.

Reduce JPG file size on Mac using Preview

Every macOS has a version of Preview, an image and PDF viewing app that lets you look over and print images or PDF files, as well as edit all kinds of image formats.

Before you begin to compress a JPEG, note that there are two types of image compression: lossless and lossy. Lossless compression means that the image quality will be retained, while, as a result of lossy compression, some photo data will be lost, impacting its quality.

Here is how to compress JPG files using Preview:

1. Right-click on the JPG file > Open with > Preview.

2. Go to Tools > Adjust Size.

3. Change image dimensions to compress the file. 

4. Check the Resulting Size section to see the estimated new file size.

5. Click OK.

6. Go to File > Export.

7. Enter a file name and drag the Quality slider to adjust size.

8. Click Save.

This way to reduce photo size by reducing quality is probably the easiest. However, if you wish to print a photo, or enlarge it later, you’ll need to compress it in a different way that won’t affect the image’s resolution.

Ways to shrink JPEG file size on Mac without losing quality

The simplest way to compress a JPEG is by changing its dimensions and resolution. However, if you do this, your image will become a lot less clear, which is not what we want most of the time.

Preview offers a near-lossless compression option that lets users retain most of the image quality. This option is quite useful for printing as it won’t change the resolution.

Here’s how to compress JPG files on Preview without losing quality:

1. Right-click on the JPG file > Open with > Preview.

2. Click File > Export.

3. Choose TIFF as the format and JPEG as the compression technique. 

4. Click Save.

5. Open the new TIFF file in Preview, then go to File ➙ Export

6. Export as a JPEG.

7. Rename and click Save.

This way, you will create a new JPEG. Its quality will be retained as much as possible, but the file size will be much smaller. You can compare the new sizes by right-clicking > Get Info.

Convert files to retain quality

Different file formats are used for different types of visual content, depending on how they handle compression. JPEGs easily lose their quality and are best suited for photos and realistic images, while PNGs and TIFFs retain their quality under compression because they use lossless compression. This means that if you are dealing with fine art and images with more text and fewer colors, you need a tool that offers multiple file formats. 

Permute is a quick image, audio and video converter, which handles all file formats and can turn one into another in a matter of a few clicks. Not mentioning quick batch file conversion or video file format conversions, Permute is an app that can turn video into audio (and vice versa), and help you prepare your files for going onto a virtual drive, by quickly converting them to ISO.

It takes three easy steps to convert your files using Permute:

1. Launch the app
2. Drag your file into the main window or onto the dock icon
3. Choose the target device or format and click Start

You are all set — your files will be converted into your desired format in seconds. Also, check out how to convert HEIC to JPG to reduce size.

How to compress photos in bulk

Since most of us have hundreds of photos saved on our devices, it’s rare that we’d want to reduce the file size of just one image. A more likely scenario would be wanting to shrink the size of the whole folder.

If you haven’t been organizing your folders before, now is a good time to start, since you’ll need to arrange the photos you want to compress into a single folder. That might be the hardest step of the process.

From there, you’ll be able to compress photos using no other devices, but your Mac:

1. Right-click on the folder of images you want to compress
2. Click on Compress “Folder Name”
3. Wait for the new “.zip” folder to be created

That new “.zip” file is your folder of compressed images. When you want to use those photos again, you simply have to double click that “.zip” folder to unzip it and extract your images.

Compress quickly with PhotoBulk

If you find the above methods a hassle, you can always turn to a secure third-party app to do the JPEG file compression for you. PhotoBulk is an image editor designed precisely for handling groups of photos at once. Time is the most precious commodity, so why waste it on compressing, renaming, and formatting multiple images by hand, when software has been designed to do it all for you! The app has a user-friendly interface and is intuitive in navigation. 

Here’s how to compress JPG files on Mac using PhotoBulk:

1. Launch PhotoBulk
2. Drag and drop all the images that require optimization into the editing window
3. Click Optimize and select desired optimization settings
4. Click Start and choose the way you want optimized images to be saved
5. Hit Save and wait for the app to process your images

Compress and resize with Squash

Another efficient way to shrink JPEG file size on Mac is by using Squash — an app created specifically for working on multiple files at the same time. Squash lets you enhance images, add watermarks, convert, rename, and resize — all in bulk. It’s fast and straightforward, making it a go-to instrument in image processing.

Here’s how to reduce JPG file size with Squash:

1. Launch the app
2. Drag and drop the images you want resized
3. Wait for the app to work its magic

Online tools to compress JPG files without installing apps

If you don’t want to install an app or use the built-in Preview, there are still some online options. Lots of users find them convenient as you only need to go to the web app, drag and drop your files, and click the conversion button. They are simple and fast, and they also tend to retain image quality while reducing the size.

That said, you can expect some strict limits. For example, TinyPNG doesn’t allow photos beyond 5MB, which can be annoying as most modern iPhone images range between 6MB and 8MB.

Here are some popular online tools you can use to compress JPEG files on Mac or any other device:

• ShortPixel: ShortPixel essentially does it all, allowing you to resize, compress, enjoy lossy and lossless image compression, optimize images in bulk, and more. The tool is designed for all, but targets those who want to improve image quality and loading time for their websites. 

• JPEG Optimizer: This no-nonsense tool is ideal if you’re looking to reduce image size and convert them into other formats. All you have to do is enter the output format, size dimensions, and quality percentage and hit the compress button.

• TinyPNG: TinyPNG is also made to compress images for faster website loading. It boasts a range of tailored solutions for developers, designers, and website owners, such as the Tinify CDN for advanced optimization and the WordPress Plugin for automated compression.

Whether you’re using these tools to save space on your devices or make image sharing easier (no more having to use large image-sharing sites), each one has unique features that could sway you one way or the other.

You can also check out how to convert PDF to JPG using various tools and methods.

Revert image changes after saving

We’ve all been there: altering an image and then wanting to go back to the old version. Modern technology gives us that opportunity, so if you want to revert image changes to the previous version after you save it on your Mac, you can:

1. Click File ➙ Revert To
2. Select Browse All Versions
3. Choose an older version of the image you want to revert to

Most image processing apps will also have the option to go back to a stage in the editing process, so don’t worry if you’ve made a mistake in the image size or format you’ve changed it to — there is a way to go back.

How to reduce JPEG file size on Mac: Final words

Now you know several simple ways to compress a JPEG file on your Mac. Every method has its advantages, and depending on your workflow, you can choose the one that works best for you.

• Preview: Simple and quick, but only works well with a single file.

• Online tools such as TinyPNG or ShortPixel: Great when convenience is the priority, but controls are limited.

• Squash, PhotoBulk, or Permute: Great for bulk editing, and you also get more control over the size and many other edits you’d like to make.

Best of all, the three premium apps — Squash, PhotoBulk, and Permute are available to you absolutely free through the seven-day trial of Setapp. The platform has more than 260 best-in-class macOS and iOS apps that can become your effortless solution to any tech problem and beyond. Don’t take our word for it — give Setapp a try now and see for yourself!