How to Resize the Image in Preview via Dimension and Quality on Mac [Ultimate Guide]

Last Updated on October 13, 2022 by Peter Wood

As the default photo viewer of your MacBook, Preview is the initial choice to resize the images. Whether you need to resize an image on a MacBook via the dimension for a website or reduce the quality of an email, you can always find the detailed process to resize images in Preview easily. But if you need to preserve the original quality or resize images in batch, here you can find the best alternative from the article.

How to Resize the Image in Preview

Part 1: How to Resize the Dimension of Images in Preview on Mac

Preview is the default photo viewer, which provides the basic features to edit and manage the photos, including resizing the dimension and resolution of the images on Mac. But you have to have copies of the original images to avoid replacing them by the resized ones.

Step 1: Double click any photo you want to resize on your Mac to open it with the Preview app. Of course, you can right-click the desired photo. Choose the Preview app from the Open With drop-down list.

Step 2: Once you have imported the desired images, you can click the Tools option and choose the Adjust Size button to adjust the different parameters for resizing images in Preview.

Import Photos for Resizing Preview

Step 3: In the pop-up dialog box, you can select a preset from the Fit into list. When you need to retain the original quality, you can deselect the Resample image option before changing the width and height.

Change Dimension Preview

Note: Besides the width and height, select different image dimensions, such as inches, pixels, percentages, centimeters, millimeters points, and others to reduce the size of images.

Step 4: Preview the photo size within the Resulting Size window. If you are satisfied with the image size, you can click the OK button to save the resized images in Preview.

Part 2: How to Resize the Resolution of Images in Preview on Mac

If you just need to share some large photos to an Email or other app, resizing the resolution of images in Preview on Mac is a nice choice. When you need to resize multiple photos at the same time, you have to display them in the same window beforehand.

Step 1: Go to the Preview app on your Mac and choose the Preferences option. Select the Images tab and check the Open all files in one window next to When opening files.

Open All Image Preview

Step 2: Open the desired images with Preview, you can click the Tools menu and choose the Adjust Size button to tweak the photo qualities for the images imported to the program.

Step 3: In the popup toolbar, you can enter the desired resolution you want to change in the Resolution column. Preview the output size before clicking the OK button to resize images in batch with Preview.

Change Resolution Preview

Part 3: The Best Preview Alternative to Resize Images on Mac

Preview just provides the basic methods to resize the image as mentioned above. But is there a method to resize the photos without losing the quality? It seems impossible for most of the photo resizers. WidsMob ImageConvert is the all-in-one Preview alternative to resize photos.

Besides the basic features to resize the images via dimension or resolution, you can also enlarge the resolution with AI technology, and resize pictures to WebP or AVIF without losing quality. Moreover, it provides the preset feature that enables you to custom the resizing presets accordingly.

1. Resize JPEG, PNG, BMP, WebP, GIF, AVIF, ICN, and more in a batch.

2. Tweak width/height/resolution, adjust the orientation, and add a watermark.

3. Provide AI technology to enhance and upscale the photo quality easily.

4. Custom the presets for resizeing images with multiple settings in one click.

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Step 1: Once you have installed WidsMob ImageConvert, you can launch the program on your computer. Click the Add button to select the desired images you want to convert. Moreover, you can double-click the desired image to preview the file.

Import Photo to Resize ImageConvert

Step 2: Enable the Resize option to choose the Free mode. Enter the width, height, and resolution to resize the images as a Preview alternative. Moreover, you can also check the Enlarge Small Images option to get the desired images on your Mac.

Resize Photos Dimension ImageConvert

Step 3: Click the Batch Convert button to save the resized image. After that, you can select the destination folder, file format, and quality. Moreover, you can also check the Overwrites exist files option to replace the original images or create new ones.

Batch Convert Image ImageConvert

Step 4: If you need to resize the images for the same size frequently, you can click the Plus button and name the preset for resizing. Click the OK button to add the preset, and you can apply the resizing method to photos in one click the next time.

Create Preset for Resizing ImageConvert

Step 5: Besides the basic resizing methods, it also provides the AI resizing to upscale the image resolution. Just click the AI Super Resolution icon to scale the images, such as 2X, 3X, and 4X. After that, you can click the Apply button to upscale the images.

AI Super Resolution Resize ImageConvert

Note: When you resize images for a website with the original quality, you only need to choose the AVIF or WebP as the output format. It will retain the original quality and reduce the file size.

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Part 4: FAQs about Resizing Images in Preview on Mac

1Is there a method to resize images in Preview without losing quality?
In depends. If you just need to reduce the size of the image, you can simply discard the other information from the image. Of course, you can choose the professional photo converter to save the images to WebP or AVIF.
2Why the images are not the correct size in Preview on Mac?
Usually, the images display the same size on screen. Make sure you have already changed the default 100% scale settings to your preference. Before resizing images in Preview on Mac, you can check the file resolution to find whether it is suitable for your website.
3How to resize images in Preview as an Email attachment?
If you need to reduce the file size for photos as an Email attachment, you have to reduce the file size to 25MB or 20MB according to the server of Email server. Moreover, you can zip the photos to a single ZIP file into compress the size.


When you need to resize images in Preview, here is the ultimate guide you should know. Alternatively, you can find a Preview alternative to reduce or enhance the photo size, make a resizing preset, and provide the batch process with WidsMob ImageConvert.

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