How to Override width and height HTML attributes with CSS

By  on  

One of the HTML elements that frequently comes into collision with CSS is the img element. As we learned in Request Metrics' Fixing Cumulative Layout Shift Problems on DavidWalshBlog article, providing image dimensions within the image tag will help to improve your website's score. But in a world where responsive design is king, we need CSS and HTML to work together.

Most responsive design style adjustments are done via max-width values, but when you provide a height value to your image, you can get a distorted image. The goal should always be a display images in relative dimensions. So how do we ensure the height attribute doesn't conflict with max-width values?

The answer is as easy as height: auto!

/* assuming any media query */
img {
  /* Ensure the image doesn't go offscreen */
  max-width: 500px;
  /* Ensure the image height is responsive regardless of HTML attribute */
  height: auto;
}

The dance to please users and search engines is always a fun balance. CSS and HTML were never meant to conflict but in some cases they do. Use this code to optimize for both users and search engines!

Recent Features

  • By
    CSS Gradients

    With CSS border-radius, I showed you how CSS can bridge the gap between design and development by adding rounded corners to elements.  CSS gradients are another step in that direction.  Now that CSS gradients are supported in Internet Explorer 8+, Firefox, Safari, and Chrome...

  • By
    Designing for Simplicity

    Before we get started, it's worth me spending a brief moment introducing myself to you. My name is Mark (or @integralist if Twitter happens to be your communication tool of choice) and I currently work for BBC News in London England as a principal engineer/tech...

Incredible Demos

  • By
    Form Element AJAX Spinner Attachment Using MooTools

    Many times you'll see a form dynamically change available values based on the value of a form field. For example, a "State" field will change based on which Country a user selects. What annoys me about these forms is that they'll often do an...

  • By
    Geolocation API

    One interesting aspect of web development is geolocation; where is your user viewing your website from? You can base your language locale on that data or show certain products in your store based on the user's location. Let's examine how you can...

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!