HTML preload Attribute: Reference and Examples

The preload attribute is a small instruction attached to an HTML element. Its job is to hint media buffering preference. It is easier to remember when you can see it in a real piece of markup.

What preload is used for

Hint media buffering preference. The attribute appears inside an element’s opening tag. Depending on its definition, it may take a specific string, a number, an enumerated keyword, or be a boolean attribute.

The example below uses it in a video context. Other elements may support it too, or may give the same attribute a different meaning.

Example you can try

<video controls preload="metadata" width="640">
    <source src="lesson.mp4" type="video/mp4">
    <p>Video unavailable.</p>
</video>

How the example works

Look for preload in the snippet. Here the example shows the value metadata. This is a concrete input the browser can interpret; it is not just text shown to the reader.

The effect depends on the element and the browser. Make sure the value matches what the chosen element supports.

Values and important behavior

none hints no buffering, metadata requests basic information, and auto allows broader preloading. Browsers may override these hints.

This detail matters most when the page receives user input, navigates to another document, or loads an external resource. In those cases, check the browser behavior and any server-side requirements separately.

Small practice task

Copy the code and change preload to another sensible value, or remove it entirely if it is optional. Test the difference in the browser and inspect any submitted value or network request.

Common Beginner Mistakes

• The effect depends on the element and the browser. Make sure the value matches what the chosen element supports.
• Using preload on an element that does not support it.
• Believing that an HTML hint or client-side check replaces real server validation or a security policy.

Key Takeaways

• preload is used to hint media buffering preference.
• The effect depends on the element and the browser. Make sure the value matches what the chosen element supports.
• Choose valid values and test the result instead of guessing what the browser will do.