How to Resize an Image Correctly

How to resize an image?

Whether you want to build user documentation, give a presentation, or create a website, high-quality, appropriately-sized images will help you demonstrate competence and build trust with your audience.

There are many ways to resize an image, but not all will have the same results. If you don’t resize it correctly, your image could end up stretched, blurry, or pixelated, making your finished product appear sloppy and unprofessional. 

In fact, more than two-thirds of consumers say they find the quality of product images essential when buying something online. 

And, finally, they just look better!

If you work with images often, knowing how to resize them correctly is critical. The good news is, it’s also quite simple!

Here’s what you’ll learn in this post:

Easily resize images and screen captures

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How to resize an image without stretching it

When working on a document in a program like Microsoft Word or Google Docs, it’s tempting to drag the corners of an image to make it larger or smaller. 

Don’t do it!

A photograph of a chihuahua compared to the same photograph that appears distorted and blurry from resizing incorrectly.
Dragging the corners of an image to resize it can make your image look distorted and blurry.

When scaling your image, it’s crucial to maintain the ratio of width to height, known as aspect ratio, so it doesn’t end up stretched or warped. If you need a specific width and height, you may need a mixture of resizing and cropping to get the desired result.

You definitely want to use an image editor to resize your photos correctly. For most basic image editing, including cropping and resizing, TechSmith Snagit is the perfect solution. 

Open your screenshot or image in the Snagit Editor, select “Image” from the top menu, then “Resize Image.” Before changing the dimensions, notice the lock symbol to the left of height and width.

A screen capture of an image being resized in TechSmith Snagit. The lock symbol that shows an image's aspect ratio is locked is highlighted.
Prevent an image from appearing stretched by locking the aspect ratio when changing the width or height.

With the lock activated, Snagit maintains the image’s original proportions. Now, you can adjust the height or width of your image to the desired dimensions without stretching or warping it.

How to resize an image without losing quality

Remember, too, that there’s a big difference between scaling an image down and resizing an image to make it larger. 

Most of the time, reducing an image’s size or dimensions won’t affect the image’s quality. Making an image to be larger than its original dimensions can be tricky.

An image is shown at its original size, smaller, and larger. The smaller and original image are clear and crisp. The larger image appears blurry and pixelated.
Resizing an image larger than its original dimensions can affect the quality.

In fact, rather than trying to increase an image’s size (which is almost never a great idea, It’s best to start with a high-resolution image that is larger than you need. Then, simply crop your image or scale it down to preserve its quality.

It’s also important to keep in mind that this is only true of bitmap images such as JPEGs, GIFs, or TIFFs. Vector files such as EPS or SVG, on the other hand, can be resized both larger and smaller without any loss in quality. 

Bitmap files tend to be photos or screenshots while vector images are typically graphics such as the one at the top of this post.

Optimizing your images and screenshots

By knowing how to resize your images correctly, you can show the value of your products or services in a polished and professional way. 

Here are some key things to remember when resizing images:

  • Use photo editing software to resize your image
  • Avoid stretching or distorting your images by locking the aspect ratio before making adjustments.
  • Start with a high-resolution image that is larger than you need.

Whether you’re sizing images for documentation, a website, or social media, you can quickly accomplish your goals with Snagit

Frequently asked questions:

Does resizing an image affect its quality?

It definitely can! Typically, making an image smaller will not impact the quality, but an image can suffer quality loss when scaled beyond its original size.

What is the difference between image size and image file size?

It can be easy to confuse image size with image file size. The image file size refers to how much space the file takes up on your computer. An image’s file size is measured in bytes. Image size refers to the image’s dimensions, commonly measured in pixels, inches, or centimeters.

What does DPI mean?

DPI stands for “dots per inch” and describes the resolution of an image. PPI or “pixels per inch” is also used to describe image resolution.

What is an aspect ratio?

Aspect ratio describes the width of an image compared to its height. For example, a photo with a 1:1 image ratio would be square, with equal width and height.

What are the best file formats for images?

There are many different file formats for images and choosing the right one depends on where and how you’re using an image. Common web image formats include JPEG, PNG, and GIF.

Editor’s Note: This post was originally published in January 2017 and has been updated in March 2022 for accuracy and to include new information.

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