Part 3: How to Reduce Photo Size on Mac in Preview Of course, you can also resize photos on Mac by converting PNG, BMP and SVG to JPEG. When you convert RAW to JPEG with a smaller size, you will remove the EXIF information and reduce some of the photo quality. If you have a RAW image, which contains EXIF information, such as camera info, ISO, shutter speed and others. Just change or convert the file format is another easy method to shrink a photo in size. Part 2: How to Shrink Photo Size on Mac with File Format After that, you can send the compressed photos to your email as attachments. Step 3Click the “Download All” button to download the reduced photos to your MacBook. Just check the process and the reduction ratio within the online image converter. Step 2Once you have uploaded the images online, it will compress photos on your Mac automatically. Click the red “+Add Images” icon to load the desired photos into the program online. Step 1Go to the free online image converter on your MacBook with any browser. Support photos in JPEG, PNG, SVG, GIF and more other formats.Check the process and reduce ratio for the photos on the browser.Batch shrinks a large number of photos into a smaller size with ease.Drag and drop the photos online to compress and photos automatically.