The <img> tag

The <img> tag embeds an image in the document. It's a void element — it has no closing tag.

Syntax

<img src="photo.jpg" alt="Image description">

src	The image URL. Required.
alt	A text description for screen readers and for when the image fails to load. Required for accessibility.
width / height	Pixel dimensions. Setting both lets the browser reserve space and avoid layout shift (CLS).
loading	"lazy" defers loading until the image approaches the viewport.
srcset / sizes	A list of images at different densities/sizes for responsive loading.

<img src="hero.jpg" alt="Team working in the office" width="800" height="450" loading="lazy">

alt="" (empty) is correct for purely decorative images that carry no information.
Without width/height, the browser can't reserve space before the image loads, which causes content to shift.

Don't just repeat the word "image" in alt text — describe what's actually shown.
For complex images (charts, diagrams), alt should convey the data's meaning, not just its appearance.

The src attribute of img, script, video, audio, iframe: the URL of a resource to load.

The alt attribute of img: a required text description for accessibility and fallback.

How to give the browser several image variants for different screen sizes.

The loading="lazy" attribute for deferring images that are off-screen.

Format and minify HTML code online. Fully processed in your browser, nothing sent to a server.