By default, Apple devices take and save screenshots in PNG format. I take dozens of screenshots on iPhone and Mac every day for my articles. Reduce image file size by changing their format Now that you know the basics about image file size, here are some quick ways to convert large images on Mac to smaller sizes. This is because the sharper screen has more pixels and image dimensions, resulting in bigger screenshots. Screen resolution: The screenshot file size of my new retina 13-inch MacBook Pro is far more than that of my non-retina 13-inch MacBook Pro.Flash: If you use flash while shooting pictures, this will result in an image with increased file size.Camera type: Pictures taken by the front iPhone camera or the MacBook’s webcam will almost always have a smaller file size than the primary camera, which runs into several megapixels.

Image content and color depth: If there are many black portions in the image instead of white, it can have a smaller file size.But if your image is mainly text-based, PNG is better. Image format: For most pictures, JPG/JPEG tends to have a smaller file size than PNG.

Image dimensions: A 1920 x 1080 image will have a bigger file size than a 720 x 480 image.

The file size of a photo depends on various things like: Use online sites to compress images Factors on which the image file size depends

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