HTML <select> multiple and size: Multi-Select Lists

Think of filling out a sign-up page. Clear fields make the job simple; confusing fields make people leave.

What You Need to Know

Here is a small, realistic example focusing on multiple and size.

In this example: choose multiple interests.

Try the Example

Take a look at the example. We’ll explain the important lines right below it.

<form action="/topics" method="get">
    <label for="topics">Choose one or more topics</label>
    <select id="topics" name="topic" multiple size="3">
        <option value="html">HTML</option>
        <option value="css">CSS</option>
        <option value="javascript">JavaScript</option>
    </select>
    <button type="submit">Save</button>
</form>

Let’s Read the Code

multiple: Multiple allows several values or files where that control supports it.
<form>: The form groups controls and identifies where submitted data goes.
<label>: The label tells people what the input is for. A matching for/id pair makes the label clickable.
for: For connects a label or output with a control by ID.

What the example shows: The markup gives the browser a clear starting point for multiple and size. Look at the labels, names, and values rather than only the visual appearance.

What Happens in the Browser?

The HTML controls work in the browser, but saving an answer requires the example action path to be handled by a real server.

Where does the answer go? The example uses the submitted name(s) topic. Those names help the receiving server identify each answer. A label is for people; a name attribute is for the form data; an ID connects elements in the page.

Your Turn

Change one meaningful attribute, submit the form, and compare the result with the original.

Common Beginner Mistakes

Copying the example without giving the fields a clear label and a usable name.
A browser may render the control differently from another browser without changing the HTML meaning.

Key Takeaways

Choose the HTML feature that explains this task clearly.
multiple: Multiple allows several values or files where that control supports it.
Test the behavior you expect rather than trusting how the snippet looks in your editor.