How to Easily Resize Images on Any Device or Operating System

Resizing images is an important skill for anyone working with digital images. Whether you need to optimize images for your website, prepare images for print, or resize photos to share on social media, having the ability to resize images easily can save you a lot of time and frustration.

In this comprehensive guide, we will cover everything you need to know about resizing images on any device or operating system.

Why Image Resizing is Important

Here are some of the main reasons why you may need to resize images:

  • Website Optimization – Large image files can slow down your website. Resizing images to be smaller can help pages load faster.
  • Social Media – Most social platforms have requirements for image dimensions. Resizing ensures your images look good.
  • Print Projects – Images need to match print dimensions. Resizing prevents distortion or pixelation.
  • File Size Reduction – Resizing images reduces file size which saves storage space.
  • Maintain Aspect Ratio – Resizing proportionally prevents distortion of images.
  • Batch Processing – Resizing multiple images at once saves a huge amount of time.

Image Resizing Basics

Before learning how to resize images, it helps to understand some basic concepts.


Image resolution refers to the amount of detail an image can reproduce. It is measured in pixels or dots per inch (dpi). Higher resolution means more detail.

Aspect Ratio

The aspect ratio is the proportional relationship between an image’s width and height. Maintaining aspect ratio prevents distortion.


The interpolation method determines how pixels are modified when resizing an image. Different methods prioritize speed, quality, sharpness, etc.

File Size

File size measures how much storage space an image file occupies. Resizing images reduces file size which saves storage space.

File Format

Common image formats are JPG, PNG, GIF, TIFF. The format impacts things like file size, number of colors, and compression capabilities.

How to Resize Images on Windows

The easiest way to resize images on Windows is by using Paint 3D which comes pre-installed on Windows 10.

Here is how to use Paint 3D to resize images on Windows:

  1. Open Paint 3D
  2. Select the image you want to resize
  3. Click the “Resize” button on the toolbar
  4. Adjust height, width or resolution
  5. Click “Apply” then “Save As” to save resized image

Another option is to use Microsoft PowerToys which includes an image resizing utility. Simply right-click images and select “Resize Image” to batch resize files easily.

There are also free tools like XnResize or FastStone Photo Resizer that offer advanced resizing options if needed.

How to Resize Images on Mac

The Preview app included on Mac provides an easy way to resize images.

Follow these steps to resize in Preview:

  1. Open the image in Preview
  2. Click “Tools” and select “Adjust Size”
  3. Enter new dimensions or scale %
  4. Make sure “Scale Proportionally” is checked
  5. Click “OK” then “Save As” to save resized image

For more control, you can use the built-in Automator app to create batch actions for resizing multiple images at once.

Some free Mac apps like Xee, ImageOptim, or Caesium also provide advanced resizing options.

How to Resize Images on iPhone/iPad

To resize images directly on an iPhone or iPad, you can use the built-in Photos app:

  1. Open the Photos app and select an image
  2. Tap “Edit” in the upper right corner
  3. Select the crop icon in the bottom left
  4. Tap “Crop” and adjust corners to desired size
  5. Tap “Done” to save resized photo

This method allows you to crop images which is a type of resizing. Just make sure to tap “Done” again after cropping to save changes.

How to Resize Images on Android

Unlike iPhone, Android does not include built-in image resizing capabilities. However, there are several good Android apps for resizing:

Photo & Picture Resizer – Provides preset sizes or custom dimensions. Easy batch resizing.

Resize Image – Simple app for basic image resizing needs. Good for beginners.

Image Size Reducer – Compress images while resizing to reduce file size.

RealSize – Resizes images using different interpolation methods. More advanced features.

These apps provide an easy way to resize images directly on your Android device.

Online Image Resizing Tools

If you don’t want to download any software, there are many free online image resizers:

  • PicResize – Simple interface, multiple resizing options
  • ResizeImage – Easy tool for basic resizing
  • BeFunky – Creative editor with advanced features
  • ShrinkMe – Optimizes file size while resizing
  • ILoveIMG – Allows batch resizing multiple images

With online resizers, you can access the tools from any internet-connected device. Just upload images to the website and resize them there.

How to Maintain Image Quality When Resizing

When making images smaller through resizing, you typically won’t see a reduction in quality. However, enlarging images can cause them to appear pixelated or blurry.

Here are some tips for maintaining quality:

  • Start with a high-resolution image, larger than your final size
  • Use bicubic interpolation instead of nearest neighbor
  • Avoid increasing images more than 10-20% larger
  • Use sharpening filters after enlarging to sharpen details
  • Save resized JPGs with a quality setting of 90+ to minimize artifacts

As long as you don’t drastically increase image dimensions, resizing photos and images appropriately will allow them to retain high quality.


The ability to properly resize images is an invaluable skill for designers, photographers, or anyone working with digital images.

Whether you need to optimize images for the web, prepare files for print, create social media posts, or simply reduce file sizes, resizing images is a common requirement.

Thankfully, as this guide has shown, there are many straightforward ways to resize images no matter what device or operating system you use. The key is finding a method that works reliably for your specific needs.

Some require downloading software while others can be accessed directly online. But they all provide an easy way to resize digital photos and images while maintaining quality.

So the next time you need to prep some files for a website or print project, give image resizing a try using one of these handy tools!