The HTML size attribute
Quick answer
The HTML size attribute sets the visible width of an input in characters, or the number of visible options in a select. It is used on the <input> and <select> elements.
Overview
The size attribute sets the visible size of the control. It is used on form controls such as <input>, <select> and <textarea>.
It is a form-control attribute: it configures how a control behaves, what it accepts, or its initial value, working alongside the control's <label> and parent <form>. Constraint attributes also feed the browser's built-in validation.
Syntax
<input size="40">Values
| Value |
|---|
| A positive integer. |
Example
<select size="3"><option>One</option><option>Two</option><option>Three</option></select>Best practices
- Give every control a <label> so it has an accessible name.
- Treat client-side constraints as a convenience — always validate again on the server, since they can be bypassed.
- Choose the most specific input type so users get the right on-screen keyboard and built-in checks.
- Keep the submitted name and value meaningful for whatever processes the form.
Frequently asked questions
What does the size attribute do?
Sets the visible size of the control.
Are HTML form attributes enough for validation?
They give instant feedback, but client-side checks can be bypassed, so always validate on the server too.
Do form controls still need a label?
Yes. Every control needs a <label> for an accessible name, whatever attributes you set.
Which elements use the size attribute?
It is an element-specific attribute, used on form controls such as <input>, <select> and <textarea>.