If an image is too large, you can reduce its size in two ways. You can resize and lower the resolution, or you can export it in a lower quality. Here is how to reduce or reduce photo size on Mac.
How to reduce the photo size by lowering the resolution
The fastest way to reduce the photo size is to decrease the photo resolution. If a website or an application has an upper limit on the size of a photo file, try lowering the resolution first.
With the Preview app, you can do this for one image at a time or for multiple images at once. First, open the Finder app and find the image (or images) you want to resize. Then double-click the file to open it in Preview.
If Preview is not set as the default image viewer, right-click and choose Open With> Preview (we recommend taking a moment to set Preview as the default image viewer as it will make your life easier. ).
RELATED: How to Change the Default Application for a File Type in Mac OS X.
Now that the photo is open in Preview, it’s time to resize it. Click the Edit button in the top toolbar (it looks like a pen icon.). Then, from the editing options, click the Resize button (this is the multi-box icon).
In the popup first switch to the option “Pixels”. Then change the width to about 50% of the original size (you can try different resolutions). Preview immediately tells you the new file size of the image. When you are satisfied with the result, click the “OK” button.
Preview automatically saves your changes to the image, but you can use the Command + s option to manually update the image. Now you can close the preview window by clicking the red Close button in the top right corner, or you can use the keyboard shortcut Command + q instead.
When you return to the Finder window, you will see the updated file size for the photo.
How to reduce photo size by lowering quality
What if you can’t resize the image, but you still want to reduce the file size? The Preview app can help you there too. You can export an image in JPEG format with a lower quality (This feature does not support PNG format, but we will provide a solution for that in the next section.).
Open the image file in Preview to get started. Then click on the ‘File’ option in the menu bar at the top and select ‘Export’.
Once you switch to “JPEG” as the file format, you will see a “Quality” slider. Scroll to the “Least” quality side here and you will see the file size update in real time.
Since Preview exports a new image, you can edit both the name of the photo and the destination from above. When you are satisfied with the format, click the “Save” button.
Go to the designated folder in Finder and you will find the exported image ready to use. During our testing, we were able to resize a 371 KB PNG photo to a 52 KB JPEG image without having to resize or experience a significant loss of quality.
How to Compress Photos with TinyPNG
Don’t want to resize a photo, but still want to use the PNG format? Try TinyPNG.
This website uses intelligent compression to compress the PNG or JPEG file up to 90% without any noticeable loss in visual quality. Just open the TinyPNG website and drag the image files to the upload area.
Once the compression is complete, you can download the photos individually or as a ZIP archive.
As you can see in the screenshot above, TinyPNG managed to compress the 299.7 KB file to just 81.9 KB. That’s a 72% reduction in file size!
Speaking of compressing files, the Preview app doesn’t just stop with photos. You can also use the Preview app to compress PDFs!
RELATED: Compress and shrink PDFs