Resizing Images for the Web

Confused? Here are some Resources


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Cropping Versus Resizing

Crop: To remove part of the image to adjust framing.
Resize: To change the dimensions of an image file which can reduce file size.

Why Do I Need to Resize My Photos?

Often times, pictures from our digital cameras are very large. This is because there are different image resolutions for printing photos vs. simply viewing photos on the web.

Photos viewed on the web will be compressed for easier and faster downloads. 

What Are Pixels? 

Pixels are tiny squares of color and information that make up an image. Think of them as a unit of measurement for resolution. If an image on a screen is 1920x1080, then there are 1,920 pixels from one side of the screen to the other and 1,080 pixels from top to bottom. 


What is Resolution?

Resolution is the amount of detail in an image. The more pixels = more detail = higher resolution. Most camera phones today have enough megapixels to provide high-resolution photos for the web, but not recommended for larger prints. 

Print Images

Images need to be high quality and have high resolution to print. Image size for printing is determined by how many pixels-per-inch (ppi) make up an image. The number of pixels can range from a lot (300 ppi) to a little (72 ppi). When you are printing a photograph from your camera, the rule of thumb is to use the highest ppi possible for the size you need. Most printers will recommend using 300 ppi as your setting.

Web Images

The web works a little differently. To understand how image ppi affects images displayed on webpages, consider this formula: 1-1.

Pixels-per-inch is irrelevant to images on the web.

Rather, they are based on how many pixels the image has. The goal is to resize your photo to exactly what size you will be using it on the website. A general rule of thumb is that about 100 pixels = approximately 1 inch on a website. By sizing down your photos appropriately for what you are using them for, you will reduce the file size and make the page load faster.

Why use PPI then?

We recommend the setting of 72 ppi for the web. Why? Because you have to put something in the box in most image editing programs, such as Adobe Photoshop. But when Photoshop asks for ppi in the Image Size dialog, this value is used to determine how Photoshop converts the pixel dimensions of the image into printed inches.

Recommended Programs

  1. PicMonkey
    This is a great online tool for not just resizing, but editing photos. Check out this great tutorial for cropping and resizing your photos to the exact dimensions you need using PicMonkey.
  2. Lunapic
    Edit, crop, and resize photos quickly
    This is an online tool that will resize and crop a single photo for you quickly - no need to install any software onto your computer!
  4. pixlr
    pixlr is a more advanced online photo editor that will crop and resize your photos & much more.
  5. Adobe Photoshop Express App
    This app is free and gives you the basic tools in Photoshop to edit images on your phone or with the Windows 10 desktop app.
  6. OSX Image Resizer (for Mac Users)
    Have a Mac? We've still got you covered. This tutorial will show you how to use OSX to resize a large number of images quickly.
  7.  dotCMS Built-In Image Editor
    Our CMS has a built-in tool to crop, resize and adjust images that have already been uploaded. While we always recommend adjusting photos before uploading them, this tool is a quick way to adjust a photo that is already on your site.