Which attributes are essential for img?

Images are fundamental to modern web design, bringing visuals, context, and beauty to our digital experiences. But simply dropping an image file into a web page isn't enough; the HTML `<img>` tag relies on a few crucial attributes to properly display, describe, and optimize these visual elements. Understanding these essentials ensures your images look great, are accessible to everyone, and contribute positively to your site's performance.

At the very core, two attributes are absolutely non-negotiable for any image: `src` and `alt`. The `src` attribute, short for "source," tells the browser exactly where to find the image file. Without it, the browser wouldn't know which image to load, leaving a broken placeholder in its wake. Equally important is the `alt` attribute, providing "alternative text." This descriptive text is vital for accessibility, read aloud by screen readers for visually impaired users. It also displays if the image fails to load, and it's used by search engines to understand the image's content, significantly aiding SEO. Neglecting `alt` text excludes users and misses an important opportunity for discoverability.

Beyond the fundamental source and description, `width` and `height` are highly recommended for enhancing user experience and performance. These attributes specify the intrinsic dimensions of the image in pixels. While browsers can often figure out image dimensions eventually, explicitly setting them prevents what's known as "layout shift." Without them, the browser might render your text, then suddenly shift everything around once the image loads and its size is determined, creating a jarring experience. Providing `width` and `height` reserves the necessary space upfront, ensuring a smoother, more stable page layout. Modern best practices also often include `loading="lazy"` to defer loading off-screen images, but `width` and `height` remain critical for initial page rendering.

Related Keywords: HTML image, Web accessibility