How to compress a JPEG on Mac

In the digital age, social media is dominating the trend, with more and more applications turning to image-intensive formats. This makes most of us very sensitive to visual information and develop the habit of taking countless photos every day.

Avast's 2019 study shows that the number of photos people store in their mobile phone albums ranges from 400 to 1,400. Most of these photos are in JPEG format, which is the most commonly used image format for smartphones and digital cameras.

As mobile phone cameras become more and more capable of taking high-quality photos, the file size of photos has also increased. Whether you want to send these images to others or just clean up the precious storage space on your device, one of the most convenient solutions is to compress your photos to reduce their size.

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Let's learn more about how to quickly and easily reduce JPEG file size on Mac.

Use preview to reduce photo size to reduce resolution

Each macOS system comes with its own preview application, an image and PDF viewing application that allows you to view and print images or PDF files, as well as edit various image formats.

Before you start compressing JPEG, please note that there are two types of image compression: lossless compression and lossy compression. Lossless compression means that the image quality will be preserved, while lossy compression will cause some photo data to be lost, which will affect its quality.

Here is how to reduce the size of JPEG file in preview:

1. Open the app and launch the preview app
2. Click File ➙ to open
3. Find the photo you want to compress and select Open
4. Click Tools on the menu bar and select Resize
5. Select percentage or size as the adjustment value
6. Adjust the width, height, and resolution, and click OK
7. Check the result size section to make sure the new image size meets your needs
8. Select File ➙Save As to create a new copy of JPEG
9. Enter the image file name and click Save

This method of reducing the size of a photo by reducing quality is probably the easiest. However, if you want to print a photo or zoom in later, you need to compress it in a different way so that it doesn't affect the resolution of the image.

How to reduce JPEG file size without losing quality on Mac

The easiest way to compress a JPEG is to change its size and resolution. However, if you do this, your image will become blurry, which is usually not what we want.

To compress photos using the preview application on your Mac without losing their quality, follow these steps:

1. Find the image you want to resize and double-click to open it in preview
2. Click File ➙Export
3. Export as TIFF by opening the Format drop-down menu and selecting TIFF
4. Open the compression menu and select JPEG
5. Click to save
6. Open a new TIFF file in preview and go to file ➙Export
7. Export as JPEG, don't change the quality options unless you want to reduce the quality
8. Click Save, if necessary, rename the image

This way you will create a new JPEG that will reduce its size but its quality will be preserved as much as possible.

Different file formats are used for different types of visual content, depending on how they remain compressed. JPEG is prone to losing quality, best for photos and realistic images, while PNG retains its quality under compression, so it is perfect for line drawings and images containing more text and less color.

Permute is a fast image, audio and video converter that processes all file formats and converts one format to another in just a few clicks. Not only does a simple image or video file format conversion, Permute can also convert video to audio (and vice versa) and help prepare files you want to put into your virtual drive by quickly converting it to ISO.

Converting files with Permute is only three simple steps:

1. Start the application
2. Drag your file to the main window or dock icon
3. Select the target device or format and click Start

Everything is ready – your file will be converted to the desired format in seconds.

How to batch compress photos

Since most of us save hundreds of photos on our device, we rarely want to reduce the file size of just one image. More common situations are to reduce the size of the entire folder.

If you haven't sorted out the folders before, now is a good time to get started, as you need to organize the photos you want to compress into a folder. This is probably the most difficult step in the whole process.

From there, you can compress photos using any device other than your Mac:

1. Right-click on the image folder you want to compress
2. Click to compress "Folder Name"
3. Wait for the creation of a new ".zip" folder

The new ".zip" file is the folder of your compressed images. When you want to use these photos again, just double-click on the ".zip" folder to unzip and extract your images.

If you find the above method cumbersome, you can always turn to a secure third-party application to perform JPEG file compression for you.

PhotoBulk is an image editor designed for processing multiple photos at once. Time is the most precious asset, so why waste time manually compressing, renaming and formatting multiple images when there is already software that can do all the work for you!

The app has a user-friendly interface and intuitive navigation. To start, just:

1. Start PhotoBulk
2. Drag and drop all images that need to be optimized into the edit window
3. Click Optimize and select the desired optimization settings
4. Click Start and select the way to save the optimized image
5. Click Save and wait for the application to process your image

Another effective way to reduce the size of JPEG files on your Mac is to use Squash - an application created specifically to process multiple files simultaneously. Squash allows you to batch enhance images, add watermarks, convert, rename and resize them. It is fast and easy to use, making it the preferred tool for image processing.

To resize or compress photos with Squash, just:

1. Start the application
2. Drag and drop the image you want to resize
3. Wait for the app to play its magic

Recover image changes after saving

We have all encountered this situation: after modifying the image, we want to restore to the old version. Modern technology gives us this opportunity, so if you want to save images on your Mac and restore them to previous versions, you can:

1. Click File ➙Restore to
2. Select to browse all versions
3. Select the old version of the image you want to restore to

Most image processing applications also have the option to return to a certain stage in the editing process, so don't worry if you make mistakes with image size or format changes – there is a way to return.

Now you've learned several simple ways to compress JPEG on your Mac. Each method has its advantages, and you can choose the one that suits you best based on your workflow. If you want to use time for other tasks while delegating image processing to reliable and efficient applications, you can use Squash, PhotoBulk, or Permute.

Best of all, all three apps – Squash, PhotoBulk and Permute – are available completely free with the seven-day free trial of Setapp, a platform with over 230 top-notch macOS and iOS apps that can be your easy solution to any technical and other issues. Don't listen to us, try Setapp now and experience it yourself!

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