Imagine opening this page on a slow phone connection. The media should still be worth the wait and have a sensible fallback.
What You Need to Know
When an image's width and height are known before it loads, the browser can reserve its space. That prevents nearby text and buttons from jumping as the image appears.
Try the Example
Take a look at the example. We’ll explain the important lines right below it.
<figure>
<img src="images/robot.jpg" alt="A small robot on a desk" width="800" height="450">
<figcaption>Our class robot project.</figcaption>
</figure>Let’s Read the Code
- <img>: The img displays a picture; its alt is the text alternative.
- src: Src identifies a resource path for images, frames, or media.
- width: Width gives a preferred or intrinsic media width, depending on the element.
Read the named elements and attributes together. They explain how the browser connects this feature to the rest of the page.
What Happens in the Browser?
The paths shown here refer to files in your own example project. Put real images and recordings in those locations before expecting them to load.
What if the resource is missing? Test the page with the media path temporarily broken. The surrounding text should still explain the important idea, and controls should remain understandable. This is especially important for slow connections and accessibility.
Your Turn
Try changing one file path or attribute. Notice whether the browser falls back to another source or shows missing content.
Common Beginner Mistakes
- Leaving out real media files or understandable text alternatives.
- Always check keyboard access, readable alternatives, and any missing files; a perfect player layout does not guarantee accessible content.
Key Takeaways
- When an image's width and height are known before it loads, the browser can reserve its space.
- <img>: The img displays a picture; its alt is the text alternative.
- If the resource cannot load, users still need enough text to understand what was meant to be there.